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  <title>Mom -- Typesetting Macros</title>
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  <td><a href="toc.html">Back to Table of Contents</a></td>
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<h1 id="typesetting" class="docs">The typesetting macros</h1>

<div id="typesetting-macros-mini-toc" class="mini-toc">
<div class="mini-toc-col-1">
<ul class="no-enumerator">
  <li class="list-head"><a href="#typesetting-macros">Introduction</a></li>
  <li class="list-head"><a href="#page-setup-intro">Paper and page setup</a>
  <ul>
    <li class="item"><a href="#page-setup-note"><i>Important note on page dimensions &amp; papersize</i></a></li>
    <li class="item"><a href="#index-page-setup">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#basic-params-intro">Basic typesetting parameters</a>
  <ul>
    <li class="item"><a href="#index-basic">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#justification-intro">Justification and quadding/
    <br/>
    <span style="margin-left: 1em;">breaking and joining lines</span></a>
  <ul>
    <li class="item"><a href="#index-justification">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#refinements-intro">Typographic refinements</a>
  <ul>
    <li class="item"><a href="#index-refinements">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#modifications-intro">Type modifications (pseudo font styles)</a>
  <ul class="no-enumerator">
    <li class="item"><a href="#index-modifications">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#aldrld-intro">Vertical movements</a>
  <ul class="no-enumerator">
    <li class="item"><a href="#index-aldrld">Macro list</a>
    </li>
  </ul></li>
</ul>
</div>
<div class="mini-toc-col-2">
  <ul class="no-enumerator">
  <li class="list-head"><a href="#tabs-intro">Tabs</a>
  <ul class="no-enumerator">
    <li class="item"><a href="#typesetting-tabs">Typesetting tabs</a>
    <ul style="margin-left: -.5em;">
      <li class="item" style="margin-left: -.5em; list-style-type: circle;"><a href="#typesetting-tabs-tut">Quickie tutorial on typesetting tabs</a></li>
    </ul></li>
    <li class="item"><a href="#string-tabs">String tabs</a>
    <ul style="margin-left: -.5em;">
      <li class="item" style="margin-left: -.5em; list-style-type: circle;"><a href="#string-tabs-tut">Quickie tutorial on string tabs</a></li>
    </ul></li>
    <li class="item"><a href="#index-tabs">Macro list</a></li>
  </ul></li>
  <li class="list-head"><a href="#multicolumns-intro">Multiple columns</a>
  <ul class="no-enumerator">
    <li class="item"><a href="#index-multicolumns">Macro list</a>
    </li>
  </ul></li>
  <li class="list-head"><a href="#indents-intro">Indents</a>
  <ul class="no-enumerator">
    <li class="item"><a href="#indents-handling">How mom handles indents</a></li>
    <li class="item"><a href="#index-indents">Macro list</a>
    </li>
  </ul></li>
  <li class="list-head"><a href="goodies.html#goodies">Goodies</a>
  <ul class="no-enumerator">
    <li class="item"><a href="goodies.html#goodies-macros">Macro list</a>
    </li>
  </ul></li>
  <li class="list-head"><a href="inlines.html#top">Inline escapes</a>
  <ul class="no-enumerator">
    <li class="item"><a href="inlines.html#index-inlines">List of inline escapes</a>
    </li>
  </ul></li>
  <li class="list-head"><a href="color.html#colored-text-intro">Coloured text</a>
  <ul class="no-enumerator">
    <li class="item"><a href="color.html#colored-text-macros">Macro list</a></li>
  </ul></li>
</ul>
</div>
</div>

<div class="rule-medium"><hr/></div>

<h2 id="typesetting-intro" class="docs">Introduction</h2>

<p>
Mom&#8217;s typesetting macros provide access to groff&#8217;s
typesetting capabilities.  Aside from controlling basic type
parameters (family, font, line length, point size, leading),
mom&#8217;s macros fine-tune wordspacing, letterspacing, kerning,
hyphenation, and so on.  In addition, mom has true typesetting tabs,
string tabs, multiple indent styles, line padding, and a batch of
other goodies.
</p>

<p>
In some cases, mom&#8217;s typesetting macros merely imitate groff
primitives.  In others, they approach typesetting concerns in
conceptually new ways (for groff, at least).  This should present
no problem for newcomers to groff who are learning mom.  Old groff
hands should be careful.  Just because it looks like a duck and
walks like a duck does not, in this instance, mean that it is a
duck.  When using mom, stay away from groff primitives if mom
provides a macro that accomplishes the same thing.
</p>

<p>
Mom&#8217;s typesetting macros can be used as a standalone package,
independent of the
<a href="docprocessing.html#top">document processing macros</a>.
With them, you can typeset on-the-fly.  Book covers, your best
friend&#8217;s résumé, a poster for a lost dog&mdash;none of these
requires structured document processing (page headers, paragraphs,
heads, footnotes, etc).  What they do demand is precise control over
every element on the page.  The typesetting macros give you that
control.
</p>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="page-setup-intro" class="macro-group">Paper and page setup: paper size &amp; page margins</h2>

<p>
The page setup macros establish the physical dimensions of your page
and the margins you want it to have. Groff has defaults for these,
but I recommend setting them at the top of your files anyway unless
you&#8217;re using mom&#8217;s
<a href="docprocessing.html#docprocessing">document processing macros</a>
and are content with her defaults.
</p>

<p>
The
<a href="#paper">PAPER</a>
macro provides a shortcut for setting the page to the correct
dimensions for a number of common paper sizes.  The
<a href="#page">PAGE</a>
macro provides a convenient way of setting the page dimensions and
some or all of the page margins with a single macro.
</p>

<div class="box-notes">
<h3 id="page-setup-note" class="docs notes">Important note on page dimensions and papersize</h3>

<p style="margin-top: .5em;">
Mom&#8217;s macros for setting up the desired size of printer sheets
tell mom and groff about the page dimensions, but not the driver
responsible for generating the final PostScript file.  You must take
care of this yourself.
</p>

<p>
If you routinely print documents on the same size paper (you
probably do), the easiest way to make sure the PostScript driver
knows about your papersize is to edit the file
<br/>
<span class="pre-in-pp">
  &lt;path to groff&gt;/font/devps/DESC
</span>
In it, you will see a line that reads:
<span class="pre-in-pp">
  papersize &lt;papersize&gt;
</span>
Change <kbd>&lt;papersize&gt;</kbd> to the name of your papersize
(e.g. a4, letter, legal, etc.; a full list of valid named papersizes
that can be used in DESC is found in <kbd>man papersize</kbd>).  If
your routine papersize is non-standard (i.e. doesn&#8217;t have a
&#8220;name&#8221;) you can give the dimensions for your papersize,
separated by a comma.  The dimensions must have a
<a href="definitions.html#unitofmeasure">unit of measure</a>
appended.  Valid units of measure for papersize are
inches (<kbd>i</kbd>),
centimeters (<kbd>c</kbd>),
picas (<kbd>P</kbd>) and
points (<kbd>p</kbd>).
For example, to set up a routine papersize of 8 inches by 10 inches,
the line would look like this:
<br/>
<span class="pre-in-pp">
  papersize 8i,10i
</span>
Having set up your routine papersize, if you occasionally need to
print on sheets that do not conform to its dimensions, you must, in
addition to setting the page dimensions in your mom file, invoke
groff on the command line with the <kbd>-P-p&lt;papersize&gt;</kbd>
option.
</p>

<p>
For example, suppose your routine papersize is &#8220;letter&#8221;,
and you need to print something on a legal-sized sheet.  After
telling mom about the legal-size sheet (with either
<a href="#pagelength">PAGELENGTH</a>
and
<a href="#pagewidth">PAGEWIDTH</a>
or
<a href="#paper">PAPER</a>,
or
<a href="#page">PAGE</a>)
in your mom file, when you invoke groff to process the file, the
command would look like this:
<br/>
<span class="pre-in-pp">
  groff -mom -P-plegal
</span>
</p>

<p class="tip-bottom" style="margin-top: -1em;">
Consult <kbd>man groff</kbd>, <kbd>man grops</kbd> and <kbd>man
groff-font</kbd> for additional information concerning papersizes,
as well as information on printing in &#8220;landscape&#8221;
orientation.
</p>
</div>

<div class="macro-list-container">
<h3 id="index-page-setup" class="macro-list">Paper and page setup macros</h3>

<ul class="macro-list">
  <li><a href="#pagewidth">PAGEWIDTH</a> &ndash; page width</li>
  <li><a href="#pagelength">PAGELENGTH</a> &ndash; page length</li>
  <li><a href="#paper">PAPER</a> &ndash; common paper sizes</li>
  <li><a href="#l-margin">L_MARGIN</a> &ndash; left margin</li>
  <li><a href="#r-margin">R_MARGIN</a> &ndash; right margin</li>
  <li><a href="#t-margin">T_MARGIN</a> &ndash; top margin</li>
  <li><a href="#b-margin">B_MARGIN</a> &ndash; bottom margin</li>
  <li><a href="#page">PAGE</a> &ndash; page dimensions and margins all in one fell swoop</li>
  <li><a href="#newpage">NEWPAGE</a> &ndash; start a new page</li>
</ul>
</div>

<!-- -PAGEWIDTH- -->

<div class="macro-id-overline">
<h3 id="pagewidth" class="macro-id">Page width</h3>
</div>

<div class="box-macro-args">
Macro: <b>PAGEWIDTH</b> <kbd class="macro-args">&lt;width of printer sheet&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
The argument to PAGEWIDTH is the width of your printer sheet.
PAGEWIDTH requires a unit of measure.  Decimal fractions are
allowed.  Hence, to tell mom that the width of your printer sheet is
8-1/2 inches, you enter
<br/>
<span class="pre-in-pp">
  .PAGEWIDTH 8.5i
</span>
Please read the
<a href="#page-setup-note">Important note on page dimensions and papersize</a>
for information on ensuring groff respects your
PAGEWIDTH.
</p>

<!-- -PAGELENGTH- -->

<div class="macro-id-overline">
<h3 id="pagelength" class="macro-id">Page length</h3>
</div>

<div class="box-macro-args">
Macro: <b>PAGELENGTH</b> <kbd class="macro-args">&lt;length of printer sheet&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
PAGELENGTH tells mom how long your printer sheet is.  It works just
like PAGEWIDTH.  Therefore, to tell mom your printer sheet is 11
inches long, you enter
<br/>
<span class="pre-in-pp">
  .PAGELENGTH 11i
</span>
Please read the
<a href="#page-setup-note">Important note on page dimensions and papersize</a>
for information on ensuring groff respects your PAGELENGTH.
</p>

<!-- -PAPER- -->

<div class="macro-id-overline">
<h3 id="paper" class="macro-id">Paper</h3>
</div>

<div class="box-macro-args">
Macro: <b>PAPER</b> <kbd class="macro-args">&lt;paper type&gt;</kbd>
</div>

<p>
PAPER provides a convenient way to set the page dimensions for some
common printer sheet sizes. <kbd>&lt;paper&nbsp;type&gt;</kbd> can
be one of:
<br/>
<span class="pre-in-pp">
  LETTER       EXECUTIVE
  LEGAL        10x14
  STATEMENT    A3
  TABLOID      A4
  LEDGER       A5
  FOLIO        B4 
  QUARTO       B5
</span>
Say, for example, you have A4-sized sheets in your printer.  It&#8217;s
shorter (and easier) to enter
<br/>
<span class="pre-in-pp">
  .PAPER A4
</span>
than to remember the correct dimensions and enter
<br/>
<span class="pre-in-pp">
  .PAGEWIDTH  595p
  .PAGELENGTH 842p
</span>
Please read the
<a href="#page-setup-note">Important note on page dimensions and papersize</a>
for information on ensuring groff respects your PAPER size.
</p>

<!-- -L_MARGIN- -->

<div class="macro-id-overline">
<h3 id="l-margin" class="macro-id">Left margin</h3>
</div>

<div class="box-macro-args">
Macro: <b>L_MARGIN</b> <kbd class="macro-args">&lt;left margin&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
L_MARGIN establishes the distance from the left edge of the printer
sheet at which you want your type to start.  It may be used any
time, and remains in effect until you enter a new value.
</p>

<p>
<a href="#il">Left indents</a>
and
<a href="#tabs">tabs</a>
are calculated from the value you pass to L_MARGIN, hence it&#8217;s
always a good idea to invoke it before starting any serious
typesetting.  A unit of measure is required.  Decimal fractions are
allowed.  Therefore, to set the left margin at 3 picas (1/2 inch),
you&#8217;d enter either
<br/>
<span class="pre-in-pp">
  .L_MARGIN 3P
</span>
or
<span class="pre-in-pp">
  .L_MARGIN .5i
</span>
If you use the macros
<a href="#page">PAGE</a>,
<a href="#pagewidth">PAGEWIDTH</a>
or
<a href="#paper">PAPER</a>
without invoking L_MARGIN (either before or afterwards), mom
automatically sets L_MARGIN to 1 inch.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> L_MARGIN behaves in a special way
when you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
See
<a href="docprocessing.html#behaviour">Typesetting macros during document processing</a>
for an explanation.
</p>
</div>

<!-- -R_MARGIN- -->

<div class="macro-id-overline">
<h3 id="r-margin" class="macro-id">Right margin</h3>
</div>

<div class="box-macro-args">
Macro: <b>R_MARGIN</b> <kbd class="macro-args">&lt;right margin&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> R_MARGIN, if used, must
come after
<a href="#paper">PAPER</a>,
<a href="#pagewidth">PAGEWIDTH</a>,
<a href="#l-margin">L_MARGIN</a>
and/or
<a href="#page">PAGE</a>
(if a right margin isn&#8217;t given to PAGE).  The reason is that
R_MARGIN calculates line length from the overall page dimensions and
the left margin.  Obviously, it can&#8217;t make the calculation if
it doesn&#8217;t know the page width and the left margin.
</p>
</div>

<p>
R_MARGIN establishes the amount of space you want between the end
of typeset lines and the right hand edge of the printer sheet.  In
other words, it sets the line length.  R_MARGIN requires a unit of
measure.  Decimal fractions are allowed.
</p>

<p>
The line length macro
(<a href="#linelength">LL</a>)
can be used in place of R_MARGIN.  In either case, the last one
invoked sets the line length.  The choice of which to use is up
to you.  In some instances, you may find it easier to think of a
section of type as having a right margin.  In others, giving a line
length may make more sense.
</p>

<p>
For example, if you&#8217;re setting a page of type you know should
have 6-pica margins left and right, it makes sense to enter a left
and right margin, like this:
<br/>
<span class="pre-in-pp">
  .L_MARGIN 6P
  .R_MARGIN 6P
</span>
That way, you don&#8217;t have to worry about calculating the line
length.  On the other hand, if you know the line length for a patch
of type should be 17 picas and 3 points, entering the line length
with LL is much easier than calculating the right margin, e.g.
<br/>
<span class="pre-in-pp">
  .LL 17P+3p
</span>
If you use the macros
<a href="#page">PAGE</a>,
<a href="#pagewidth">PAGEWIDTH</a>
or
<a href="#paper">PAPER</a>
without invoking <kbd>.R_MARGIN</kbd> afterwards, mom automatically
sets R_MARGIN to 1 inch.  If you set a line length after these
macros (with
<a href="#linelength">LL</a>),
the line length calculated by R_MARGIN is, of course, overridden.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> R_MARGIN behaves in a special way when you&#8217;re
using the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
See
<a href="docprocessing.html#behaviour">Typesetting macros during document processing</a>
for an explanation.
</p>
</div>

<!-- -T_MARGIN- -->

<div class="macro-id-overline">
<h3 id="t-margin" class="macro-id">Top margin</h3>
</div>

<div class="box-macro-args">
Macro: <b>T_MARGIN</b> <kbd class="macro-args">&lt;top margin&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
T_MARGIN establishes the distance from the top of the printer
sheet at which you want your type to start.  It requires a unit of
measure, and decimal fractions are allowed.  To set a top margin of
2-1/2 centimetres, you&#8217;d enter
<br/>
<span class="pre-in-pp">
   .T_MARGIN 2.5c
</span>
T_MARGIN calculates the vertical position of the first line of type
on a page by treating the top edge of the printer sheet as a
<a href="definitions.html#baseline">baseline</a>.  Therefore,
<br/>
<span class="pre-in-pp">
  .T_MARGIN 1.5i
</span>
puts the baseline of the first line of type 1-1/2 inches beneath the
top of the page.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> T_MARGIN means something slightly
different when you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
See
<a href="docprocessing.html#tb-margins">Top and bottom margins in document processing</a>
for an explanation.
</p>
</div>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> T_MARGIN does two
things: it establishes the top margin for pages that come after
it <i>and</i> it moves to that position on the current page.
Therefore, T_MARGIN should only be used at the top of a file (prior
to entering text) or after
<a href="#newpage">NEWPAGE</a>,
like this:
<br/>
<span class="pre-in-pp" style="margin-bottom: -1em;">
  .NEWPAGE
  .T_MARGIN 6P
  &lt;text&gt;
</span>
</p>
</div>

<!-- -B_MARGIN- -->

<div class="macro-id-overline">
<h3 id="b-margin" class="macro-id">Bottom margin</h3>
</div>

<div class="box-macro-args">
Macro: <b>B_MARGIN</b> <kbd class="macro-args">&lt;bottom margin&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
B_MARGIN sets a nominal position at the bottom of the page beyond
which you don&#8217;t want your type to go.  When the bottom margin
is reached, mom starts a new page.  B_MARGIN requires a unit of
measure.  Decimal fractions are allowed.  To set a nominal bottom
margin of 3/4 inch, enter
<br/>
<span class="pre-in-pp">
  .B_MARGIN .75i
</span>
Obviously, if you haven&#8217;t spaced the type on your pages so
that the last lines fall perfectly at the bottom margin, the margin
will vary from page to page.  Usually, but not always, the last line
of type that fits on a page before the bottom margin causes mom to
start a new page.
</p>

<p>
Occasionally, owing to a peculiarity in groff, an extra line will
fall below the nominal bottom margin.  If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>,
this is unlikely to happen; the document processing macros are very
hard-nosed about aligning bottom margins.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> The meaning of B_MARGIN is slightly
different when you&#8217;re using the document processing macros.
See
<a href="docprocessing.html#tb-margins">Top and bottom margins in document processing</a>
for an explanation.
</p>
</div>

<!-- -PAGE- -->

<div class="macro-id-overline">
<h3 id="page" class="macro-id">Page</h3>
</div>

<div class="box-macro-args" style="overflow: auto;">
Macro: <b>PAGE</b> <kbd class="macro-args">&lt;width&gt;&nbsp;[ &lt;length&gt; [ &lt;lm&gt; [ &lt;rm&gt; [ &lt;tm&gt; [ &lt;bm&gt; ] ] ] ] ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;All arguments require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>,
PAGE must come after
<a href="docprocessing.html#start">START</a>.
Otherwise, it should go at the top of a document, prior to any
text.  And remember, when you&#8217;re using the document processing
macros, top margin and bottom margin mean something slightly
different than when you&#8217;re using just the typesetting macros
(see
<a href="docprocessing.html#tb-margins">Top and bottom margins in document processing</a>).
</p>
</div>

<p>
PAGE lets you establish paper dimensions and page margins with a
single macro.  The only required argument is page width.  The rest
are optional, but they must appear in order and you can&#8217;t
skip over any. <kbd>&lt;lm&gt;, &lt;rm&gt;, &lt;tm&gt;</kbd> and
<kbd>&lt;bm&gt;</kbd> refer to the left, right, top and bottom
margins respectively.
</p>

<p>
Assuming your page dimensions are 11 inches by 17 inches, and
that&#8217;s all you want to set, enter
<br/>
<span class="pre-in-pp">
  .PAGE 11i 17i
</span>
If you want to set the left margin as well, say, at 1 inch, PAGE
would look like this:
<br/>
<span class="pre-in-pp">
  .PAGE 11i 17i 1i
</span>
Now suppose you also want to set the top margin, say, at 1-1/2
inches. &lt;tm&gt; comes after &lt;rm&gt; in the optional arguments,
but you can&#8217;t skip over any arguments, therefore to set the
top margin, you must also give a right margin.  The PAGE macro would
look like this:
<br/>
<span class="pre-in-pp">
  .PAGE 11i 17i 1i 1i 1.5i
                   |   |
  required right---+   +---top margin
      margin
</span>
Clearly, PAGE is best used when you want a convenient way to tell
mom just the dimensions of your printer sheet (width and length), or
when you want to tell her everything about the page (dimensions and
all the margins), for example
<br/>
<span class="pre-in-pp">
  .PAGE 8.5i 11i 45p 45p 45p 45p
</span>
This sets up an 8-1/2 by 11 inch page with margins of 45 points
(5/8-inch) all around.
</p>

<p>
Additionally, if you invoke <kbd>.PAGE</kbd> with a top margin
argument, any macros you invoke after <kbd>.PAGE</kbd> will almost
certainly move the
<a href="definitions.html#baseline">baseline</a>
of the first line of text down by one linespace.  To compensate, do
<br/>
<span class="pre-in-pp">
  .RLD 1v
</span>
immediately before entering any text, or, if it&#8217;s feasible,
make PAGE the last macro you invoke prior to entering text.
</p>

<p>
Please read the
<a href="#page-setup-note">Important note on page dimensions and papersize</a>
for information on ensuring groff respects your PAGE dimensions and
margins.
</p>

<!-- -NEWPAGE- -->

<div class="macro-id-overline">
<h3 id="newpage" class="macro-id">Start a new page</h3>
</div>

<div class="box-macro-args">
Macro: <b>NEWPAGE</b>
</div>

<p>
Whenever you want to start a new page, use NEWPAGE, by itself with
no argument. Mom will finish up processing the current page and move
you to the top of a new one (subject to the top margin set with
<a href="#t-margin">T_MARGIN</a>).
</p>

<div class="box-tip">
<p class="tip">
<span class="experts">Experts:</span>
Prior to version 1.1.9, NEWPAGE was simply an alias of
<kbd>.bp</kbd>.  As of 1.1.9, NEWPAGE, is its own mom macro.  While
the new macro should be backwardly compatible with documents created
using pre-1.1.9 moms, I suggest that from this version onward, if
you were in the habit of using <kbd>.bp</kbd> whenever you wanted to
break to a new page, you now begin to use NEWPAGE instead.
</p>
</div>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="basic-params-intro" class="macro-group">Basic typesetting parameters</h2>

<p>
The basic typesetting parameter macros deal with fundamental
requirements for setting type: family, font, point size, leading and
line length.
</p>

<p>
If you&#8217;re using the typesetting macros only, the arguments
passed to the basic parameter macros remain in effect until
you change them.  The document processing macros handle things
differently.  See
<a href="docprocessing.html#behaviour">Typesetting macros during document processing</a>
for an explanation.
</p>

<div id="index-basic" class="macro-list-container">
<h3 class="macro-list">Basic parameter macros</h3>
<ul class="macro-list">
  <li><a href="#family">FAMILY</a> &ndash; type family</li>
  <li><a href="#font">FT</a> &ndash; font</li>
  <li><a href="#fallback-font">FALLBACK_FONT</a> &ndash; for invalid fonts</li>
  <li><a href="#ps">PT_SIZE</a> &ndash; point size of type</li>
  <li><a href="#leading">LS</a> &ndash; line spacing/leading</li>
  <li><a href="#autolead">AUTOLEAD</a> &ndash; automatic line spacing</li>
  <li><a href="#linelength">LL</a> &ndash; line length</li>
</ul>
</div>

<!-- -FAMILY- -->

<div class="macro-id-overline">
<h3 id="family" class="macro-id">Type family</h3>
</div>

<div class="box-macro-args">
Macro: <b>FAMILY</b> <kbd class="macro-args">&lt;family&gt;</kbd>
</div>
<p class="alias">
<i>Alias:</i> <b>FAM</b>
</p>

<p>
FAMILY takes one argument: the name of the
<a href="definitions.html#family">family</a>
you want.  Groff comes with a number of PostScript families, each
identified by a 1-, 2-or 3-letter mnemonic.  The standard families
are:
<br/>
<span class="pre-in-pp">
  A   = Avant Garde
  BM  = Bookman
  H   = Helvetica
  HN  = Helvetica Narrow
  N   = New Century Schoolbook
  P   = Palatino
  T   = Times Roman
  ZCM = Zapf Chancery
</span>
The argument you pass to FAMILY is the identifier at left, above.
For example, if you want Helvetica, enter
<br/>
<span class="pre-in-pp">
  .FAMILY H
</span>
</p>

<div class="box-tip" style="margin-top: -1em;">
<p class="tip-top">
<span class="note">Note:</span> The font macro
(<a href="#font">FT</a>)
lets you specify both the type family and the desired font with
a single macro.  While this saves a few keystrokes, I recommend
using FAMILY for family, and FT for font, except where doing
so is genuinely inconvenient. <kbd>ZCM</kbd>, for example,
only exists in one style: Italic (<kbd>I</kbd>).  Therefore,
<kbd>.FT&nbsp;ZCMI</kbd> makes more sense than setting the family to
<kbd>ZCM</kbd>, then setting the font to <kbd>I</kbd>.
</p>

<p id="fam-add-note" class="tip-bottom">
<span class="additional-note">Additional note:</span> As of mom,
version 1.1.9-a, if you are running a version of groff lower than
1.19.2, you must follow all FAMILY requests with a FT request,
otherwise mom will set all type up to the next FT request in the
<a href="#fallback-font">fallback font</a>.
</p>
</div>

<p style="margin-top: -.5em;">
If you are running a version of groff greater than or
equal to 1.19.2, when you invoke the FAMILY macro, mom
&#8220;remembers&#8221; the font style (Roman, Italic, etc)
currently in use (if the font style exists in the new family) and
will continue to use the same font style in the new family.  For
example:
<br/>
<span class="pre-in-pp">
  .FAMILY BM   \" Bookman family
  .FT     I    \" Medium Italic
  &lt;some text&gt;  \" Bookman Medium Italic
  .FAMILY H    \" Helvetica family
  &lt;more text&gt;  \" Helvetica Medium Italic
</span>
However, if the font style does not exist in the new family, mom
will set all subsequent type in the
<a href="#fallback-font">fallback font</a>
(by default, Courier Medium Roman) until she encounters a
<a href="#font">.FT</a>
request that&#8217;s valid for the family.  For example, assuming
you don&#8217;t have the font &#8220;Medium Condensed Roman&#8221;
(mom extension &#8220;CD&#8221;) in the Helvetica family:
<br/>
<span class="pre-in-pp">
  .FAMILY UN    \" Univers family
  .FT     CD    \" Medium Condensed
  &lt;some text&gt;   \" Univers Medium Condensed
  .FAMILY H     \" Helvetica family
  &lt;more text&gt;   \" Courier Medium Roman!
</span>
In the above example, you must follow
<kbd>.FAMILY&nbsp;H</kbd> with a FT request
that&#8217;s valid for Helvetica.
</p>

<p>
Please see the Appendices,
<a href="appendices.html#fonts">Adding PostScript fonts to groff</a>,
for information on adding fonts and families to groff, as well as
to see a list of the extensions mom provides to groff&#8217;s basic
<b>R</b>, <b>I</b>, <b>B</b>, <b>BI</b> styles.
</p>

<div class="box-tip">
<p class="tip">
<span class="experts">Experts:</span> If you add other PostScript
families to groff&#8217;s /font/devps directory, I recommend
following the groff standard for naming families and fonts.  For
example, if you add the Garamond family, name the font files
<br/>
<span class="pre-in-pp">
  GARAMONDR
  GARAMONDI
  GARAMONDB
  GARAMONDBI
</span>
GARAMOND then becomes a valid family name you can pass to FAMILY.
(You could, of course, shorten GARAMOND to just G, or GD.) <b>R</b>,
<b>I</b>, <b>B</b>, and <b>BI</b> after GARAMOND are the roman,
italic, bold and bold-italic fonts respectively.
</p>
</div>

<!-- -FT- -->

<div class="macro-id-overline">
<h3 id="font" class="macro-id">FT</h3>
</div>

<div class="box-macro-args">
Macro: <b>FT</b> <kbd class="macro-args">R | I | B | BI | &lt;any other valid font style&gt;</kbd>
</div>
<p class="alias">
<i>Alias:</i> <b>FONT</b>
</p>

<p>
By default, groff permits FT to take one of four possible arguments
specifying the desired font:
<br/>
<span class="pre-in-pp">
  R  = (Medium) Roman
  I  = (Medium) Italic
  B  = Bold (Roman)
  BI = Bold Italic
</span>
For example, if your
<a href="definitions.html#family">family</a>
is Helvetica, entering
<br/>
<span class="pre-in-pp">
  .FT B
</span>
will give you the Helvetica bold
<a href="definitions.html#font">font</a>.
If your family were Palatino, you&#8217;d get the Palatino bold
font.
</p>

<p>
(As of mom, version 1.1.9-a, the range of arguments that can be
passed to FT has been considerably extended, allowing access to a
greater variety of font
<a href="definitions.html#weight">weights</a>
and
<a href="definitions.html#shape">shapes</a>.
Please see the
<kbd><a href="#font-note">NOTE</a></kbd>,
below.)
</p>

<p>
How mom reacts to an invalid argument to FT depends on which version
of groff you&#8217;re using.  If your groff version is greater than
or equal to 1.19.2, mom will issue a warning and, depending on how
you&#8217;ve set up the
<a href="#fallback-font">fallback font</a>,
either continue processing using the fallback font, or abort
(allowing you to correct the problem).  If your groff version is
less than 1.19.2, mom will silently continue processing, using
either the fallback font or the font that was in effect prior to the
invalid FT call.
</p>

<p>
FT will also accept, as an argument, a full family+font name.  For
example,
<br/>
<span class="pre-in-pp">
  .FT HB
</span>
will set subsequent type in Helvetica Bold.  However, I strongly
recommend keeping family and font separate except where doing so is
genuinely inconvenient.
</p>

<p>
For inline control of fonts, see
<a href="inlines.html#inline-fonts-mom">Inline Escapes, font control</a>.
</p>

<div id="font-note" class="box-tip">
<p class="tip">
<span class="note">Note:</span> mom, versions 1.1.9-a and higher,
considerably extends the range of arguments you can pass to FT,
making it more convenient to add and access fonts of differing
<a href="definitions.html#weight">weights</a>
and
<a href="definitions.html#shape">shapes</a>
within the same family.  Have a look
<a href="appendices.html#style-extensions">here</a>
for a list of the weight/style arguments mom
allows.
</p>
</div>

<p>
Be aware, though, that you must have the fonts, correctly installed
and named, in order to use the arguments.  (See
<a href="appendices.html#howto">How to create a PostScript font for use with groff</a>
for how to add fonts to groff.)  Please also read the
<a href="#fam-add-note">ADDITIONAL NOTE</a>
found in the description of the FAMILY macro.
</p>

<!-- -FALLBACK_FONT- -->

<div class="macro-id-overline">
<h3 id="fallback-font" class="macro-id">Fallback font</h3>
</div>

<div class="box-macro-args">
Macro: <b>FALLBACK_FONT</b> <kbd class="macro-args">&lt;fallback font&gt; [ ABORT | WARN ]</kbd>
</div>

<p>
In the event that you pass an invalid argument to
<a href="#font">.FAMILY</a>
(i.e. a non-existent family), mom, by default, uses the fallback
font, Courier Medium Roman (CR), in order to continue processing
your file.
</p>

<p>
If you&#8217;d prefer another fallback font, pass FALLBACK_FONT the
full family+font name of the font you&#8217;d like.  For example, if
you&#8217;d rather the fallback font were Times Roman Medium Roman,
<br/>
<span class="pre-in-pp">
  .FALLBACK_FONT TR
</span>
would do the trick.
</p>

<p>
Additionally, if your version of groff accepts accepts &#8221;<kbd>.if
F</kbd>&#8221; and &#8221;<kbd>.if S</kbd>&#8221; (see
<a href="#fam-add-note">above</a>),
mom issues a warning whenever a font style set with
<a href="#font">FT</a>
does not exist, either because you haven&#8217;t registered the
style (see
<a href="appendices.html#register-style">here</a>
for instructions on registering styles), or because the font style
does not exist in the current family set with
<a href="#family">FAMILY</a>.
By default, mom then aborts, which allows you to correct the
problem.
</p>

<p>
If you&#8217;d prefer that mom not abort on non-existent fonts,
but rather continue processing using a fallback font, you can pass
FALLBACK_FONT the argument <kbd>WARN</kbd>, either by itself, or in
conjunction with your chosen fallback font.
</p>

<p>
Some examples of invoking FALLBACK_FONT:
</p>

<ul class="no-enumerator" style="margin-left: -1em;">
<li style="margin-top: -.5em;">
<kbd>.FALLBACK_FONT WARN</kbd>
<br/>
mom will issue a warning whenever you try to access a non-existent
font but will continue processing your file with the default
fallback font, Courier Medium Roman.
<br/>
</li>
<li style="margin-top: .5em;">
<kbd>.FALLBACK_FONT TR WARN</kbd>
<br/>
mom will issue a warning whenever you try to access a non-existent
font but will continue processing your file with a fallback font of
Times Roman Medium Roman; additionally, &#8220;TR&#8221; will be
the fallback font whenever you try to access a family that does not
exist.
</li>
<li style="margin-top: .5em;">
<kbd>.FALLBACK_FONT TR ABORT</kbd>
<br/>
mom will abort whenever you try to access a non-existent font, and
will use the fallback font &#8220;TR&#8221; whenever you try to
access a family that does not exist.
</li>
</ul>

<p>
If, for some reason, you want to revert to ABORT, just enter
<kbd>.FALLBACK_FONT&nbsp;ABORT</kbd> and mom will once again abort
on font errors.
</p>

<!-- -PT_SIZE- -->

<div class="macro-id-overline">
<h3 id="ps" class="macro-id">Point size of type</h3>
</div>

<div class="box-macro-args">
Macro: <b>PT_SIZE</b> <kbd class="macro-args">&lt;size of type in points&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Does not require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
PT_SIZE (Point Size) takes one argument: the size of type in points.
Unlike most other macros that establish the size or measure of
something, PT_SIZE does not require that you supply a unit of
measure since it&#8217;s a near universal convention that type size
is measured in points.  Therefore, to change the type size to, say,
11 points, enter
<br/>
<span class="pre-in-pp">
  .PT_SIZE 11
</span>
Point sizes may be fractional (e.g.  10.25 or 12.5).
</p>

<p>
You can prepend a plus or a minus sign to the argument to PT_SIZE,
in which case the point size will be changed by + or - the original
value.  For example, if the point size is 12, and you want 14, you
can do
<br/>
<span class="pre-in-pp">
  .PT_SIZE +2
</span>
then later reset it to 12 with
<span class="pre-in-pp">
  .PT_SIZE -2
</span>
The size of type can also be changed inline.  See
<a href="inlines.html#inline-size-mom">Inline Escapes, changing point size</a>.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> It is unfortunate that the
<kbd>pic</kbd> preprocessor has already taken the name,
<kbd>PS</kbd>, and thus mom&#8217;s macro for setting point
sizes can&#8217;t use it.  However, if you aren&#8217;t using
<kbd>pic</kbd>, you might want to
<a href="goodies.html#alias">alias</a>
PT_SIZE as PS, since there&#8217;d be no conflict.  For example
<br/>
<span class="pre-in-pp">
  .ALIAS PS PT_SIZE
</span>
would allow you to set point sizes with <kbd>.PS</kbd>.
</p>
</div>

<!-- -LS- -->

<div class="macro-id-overline">
<h3 id="leading" class="macro-id">Line spacing/leading</h3>
</div>

<div class="box-macro-args">
Macro: <b>LS</b> <kbd class="macro-args">&lt;distance between lines&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Does not require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
LS (Line Space) takes one argument: the distance you want, typically
in points, from baseline to baseline of type.  The argument may be
fractional (e.g. 12.25 or 14.5).  Like PT_SIZE, LS does not require
a unit of measure, since
<a href="definitions.html#leading">leading</a>
is most often given in points.  Therefore, to set the linespace to
14 points, you would enter
<br/>
<span class="pre-in-pp">
  .LS 14
</span>
However, if you wish, you may specify a unit of measure by appending
it directly to the argument passed to LS.  For example, if you want
a linespace of 1/4 of an inch, enter
<br/>
<span class="pre-in-pp">
  .LS .25i
</span>
You can prepend a plus or a minus sign to the argument to LS, in
which case the line spacing will be changed by + or - the original
value.  For example, if the line spacing is 14 points, and you want
17 points, you can do
<br/>
<span class="pre-in-pp">
  .LS +3
</span>
then later reset it to 14 points with
<br/>
<span class="pre-in-pp">
  .LS -3
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="experts">Experts:</span> LS should not be confused with
the groff primitive <kbd>.ls</kbd>. LS acts like
<kbd>.vs</kbd>. mom does not provide a macro analogous to
<kbd>.ls</kbd>.
</p>
</div>

<!-- -AUTOLEAD- -->

<div class="macro-id-overline">
<h3 id="autolead" class="macro-id">Automatic line spacing</h3>
</div>

<div class="box-macro-args">
Macro: <b>AUTOLEAD</b> <kbd class="macro-args">&lt;amount of automatic leading&gt; [FACTOR]</kbd>
</div>
<p class="requires">
&bull;&nbsp;Does not require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
Without the <kbd>FACTOR</kbd> argument, AUTOLEAD calculates the
linespace for you by adding its argument to the current point size
of type. All subsequent
<a href="#ps">PT_SIZE</a>
requests automatically update the linespacing by the autolead amount.
</p>

<p>
Used in this way, AUTOLEAD does not require a unit of measure;
points is assumed.  However, you may use an alternate unit of
measure by appending it to the argument.  The argument may be a
decimal fraction (e.g. .5 or 2.75).
</p>

<p>
As an example, if your current point size of type is 12, entering
<br/>
<span class="pre-in-pp">
  .AUTOLEAD 2
</span>
changes the linespace to 14 points, regardless any linespacing
already in effect.  From here on, every change to the size of type
(with PT_SIZE, not
<a href="definitions.html#inlines">inline</a>)
changes the linespace as well.  If you decrease the type size to 9
points, the leading decreases to 11 points.  If you increase the
type size to 16 points, the leading increases to 18 points.
</p>

<p>
Automatic updating of the linespacing continues until you enter a
&#8220;manual&#8221; line space value with
<a href="#leading">LS</a>.
</p>

<p>
If you give AUTOLEAD the optional FACTOR argument, AUTOLEAD
calculates the line space as a factor of the
<a href="definitions.html#numericargument">numeric argument</a>
you gave AUTOLEAD.  For example, if your point size is 12,
<br/>
<span class="pre-in-pp">
  .AUTOLEAD 1.125 FACTOR
</span>
sets the leading at 13.5 points.  If you change the point size to
14, the leading automatically changes to 15.75 (14 x 1.125).
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> There&#8217;s no need to prepend a
plus sign
(<kbd>+</kbd>)
to AUTOLEAD&#8217;s argument, although you may do so if you wish.
</p>
</div>

<!-- -LL- -->

<div class="macro-id-overline">
<h3 id="linelength" class="macro-id">Line length</h3>
</div>

<div class="box-macro-args">
Macro: <b>LL</b> <kbd class="macro-args">&lt;line length&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
LL (Line Length) takes one argument: the distance from the left
margin of the page to the maximum allowable point on the right at
which groff should place type.  The line length, in other words, as
the macro suggests.
</p>

<p>
LL requires a unit of measure.  Therefore, to set the line length to
39 picas, you would enter
<br/>
<span class="pre-in-pp">
  .LL 39P
</span>
As with other macros that require a unit of measure, the argument to
LL may be fractional.  For example,
<br/>
<span class="pre-in-pp">
  .LL 4.5i
</span>
sets the line length to 4-1/2 inches.
</p>

<p>
Additionally, you may express a new line length relative to the
current line length by prepending a plus or minus sign to the
argument.  Thus, if you wanted to increase the line length by 3
<a href="definitions.html#picaspoints">points</a>, you could
do
<br/>
<span class="pre-in-pp">
  .LL +3p
</span>
This is especially handy when you want to &#8220;hang&#8221;
punctuation outside the right margin since you can pass
groff&#8217;s
<a href="inlines.html#inline-stringwidth-groff"><kbd>\w</kbd></a>
escape as the argument to LL, like this:
<br/>
<span class="pre=in-pp">
  .LL +\w'.'u
</span>
The above example increases the current line length by the width of
a period.  Notice that you must append the
<a href="definitions.html#unitofmeasure">unit of measure</a>,
<b>u</b>, to the escape since LL requires a unit of measure.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> The right margin macro,
<a href="#r-margin">(R_MARGIN)</a>,
can also be used to set line length.
</p>
</div>

<div class="rule-short"><hr/></div>

<!-- ==================================================================== -->

<h2 id="justification-intro" class="macro-group">Justification and quadding/breaking and joining lines</h2>

<p>
The justification and quadding macros deal with how type aligns
along the left and right margins.  In a nutshell, type either aligns
at the left margin, at the right margin, at both margins, or at
neither margin (centred).
</p>

<p>
These macros also determine whether or not
<a href="definitions.html#inputline">input lines</a>
are joined and
<a href="definitions.html#filled">filled</a>
during output.
</p>

<p>
Additionally, macros that deal with how to break
<a href="definitions.html#outputline">output lines</a>
are covered in this section, as is the
<a href="definitions.html#inlines">inline escape</a>
for joining input lines.
</p>

<p>
You may encounter some words here that are unfamiliar.  Refer to
<a href="definitions.html#typesetting">Typesetting terms</a>
and
<a href="definitions.html#groff">Groff terms</a>
for an explanation.
</p>

<div id="index-justification" class="macro-list-container">
<h3 class="macro-list">Justification and quadding/breaking and joining lines macros</h3>
<ul class="macro-list">
  <li>Fill modes
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#justify">JUSTIFY</a> &ndash; set lines justified</li>
    <li><a href="#quad">QUAD</a> &ndash; set filled lines flush left, right or centred</li>
  </ul></li>
  <li>Nofill modes
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#lrc">LEFT</a> &ndash; set non-filled lines flush left</li>
    <li><a href="#lrc">RIGHT</a> &ndash; set non-filled lines flush right</li>
    <li><a href="#lrc">CENTER</a> &ndash; set non-filled lines centred</li>
  </ul></li>
  <li>Breaking lines
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#br">BR</a> &ndash; manually break an output line</li>
    <li><a href="#el">EL</a> &ndash; break a line without advancing to the next output line</li>
    <li><a href="#space">SPACE</a> &ndash; break a line and add space before the next output line</li>
    <li><a href="#spread">SPREAD</a> &ndash; break and force-justify an output line</li>
  </ul></li>
  <li>Joining input lines in <a href="definitions.html#filled">nofill mode</a>
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#join">\c</a> inline escape</li>
  </ul></li>
</ul>
</div>

<!-- -JUSTIFY- -->

<div class="macro-id-overline">
<h3 id="justify" class="macro-id">Justify lines</h3>
</div>

<div class="box-macro-args">
Macro: <b>JUSTIFY</b>
</div>

<p class="requires">
(See
<a href="definitions.html#filled">fill mode</a>
for a definition of the difference between &#8220;fill&#8221; and
&#8220;no-fill&#8221; modes.)
</p>

<p>
JUSTIFY doesn&#8217;t take an argument. 
<a href="definitions.html#inputline">Input lines</a>
after JUSTIFY are
<a href="definitions.html#filled">filled</a>
and
<a href="definitions.html#just">justified</a>
upon output.
</p>

<p>
To break lines and prevent them from being filled and justified, use
the
<a href="#br">BR</a>
macro.
</p>

<!-- -QUAD- -->

<div class="macro-id-overline">
<h3 id="quad" class="macro-id">Quad lines left, right, or centre</h3>
</div>

<div class="box-macro-args">
Macro: <b>QUAD</b> <kbd class="macro-args">L | LEFT | R | RIGHT | C | CENTER | J | JUSTIFY</kbd>
</div>

<p class="alias" style="margin-bottom: 0;">
<i>Alias:</i> <b>FILL</b>
</p>

<p class="requires">(See
<a href="definitions.html#filled">fill mode</a>
for a definition of the difference between &#8220;fill&#8221; and
&#8220;no-fill&#8221; modes.)
</p>

<p>
QUAD takes one argument: the direction in which lines should be
<a href="definitions.html#quad">quadded</a>.
<a href="definitions.html#inputline">Input lines</a>
after QUAD are 
<a href="definitions.html#filled">filled</a>
upon output.
</p>

<p>
If <kbd>L</kbd> or <kbd>LEFT</kbd>, type is set flush along the left
margin.
</p>

<p>
If <kbd>R</kbd> or <kbd>RIGHT</kbd>, type is set flush along the
right margin.
</p>

<p>
If <kbd>C</kbd> or <kbd>CENTER</kbd> type is set centred on the
current line length.
</p>

<p>
<kbd>J</kbd> and <kbd>JUSTIFY</kbd> justify text, and are
included as a convenience only.  Obviously, if text is
justified, it isn&#8217;t quadded. <kbd>.QUAD&nbsp;J</kbd> and
<kbd>.QUAD&nbsp;JUSTIFY</kbd> have exactly the same effect as
<a href="#justify">JUSTIFY</a>.
</p>

<p>
To break lines and prevent them from being filled, use the
<a href="#br">BR</a>
macro.
</p>

<!-- -LEFT, RIGHT, CENTER- -->

<div class="macro-id-overline">
<h3 id="lrc" class="macro-id">Set lines flush left, right or centered in no-fill mode</h3>
</div>

<div class="box-macro-args">
Macro: <b>LEFT</b>
<br/>
Macro: <b>RIGHT</b>
<br/>
Macro: <b>CENTER</b> &nbsp;(alias CENTRE)
</div>

<p class="requires">
(See
<a href="definitions.html#filled">no-fill mode</a>
for a definition of the difference between &#8220;fill&#8221; and
&#8220;no-fill&#8221; modes.)
</p>

<p>
LEFT, RIGHT and CENTER let you enter text on a line for line basis
without having to use the
<a href="#br">BR</a>
macro after each line.  Consider the following:
<br/>
<span class="pre-in-pp">
  .QUAD LEFT
  So runs my dream, but what am I?
  .BR
  An infant crying in the night
  .BR
  An infant crying for the light
  .BR
  And with no language but a cry.
  .BR
</span>
Because text after <kbd>.QUAD LEFT</kbd> is
<a href="definitions.html#filled">filled</a>,
you have to use the
<a href="#br">BR</a>
macro to prevent the lines from running together.  Not only is this
annoying to type, it&#8217;s awkward to read in a text editor.  Much
better to do
<br/>
<span class="pre-in-pp">
  .LEFT
  So runs my dream, but what am I?
  An infant crying in the night
  An infant crying for the light
  And with no language but a cry.
</span>
</p>

<div class="box-important" style="margin-top: -.5em;">
<p class="tip">
<span class="important">IMPORTANT:</span> Because LEFT,
RIGHT and CENTER are nofill modes, groff does not always respect the
current line length.
<a href="definitions.html#inputline">Input lines</a>
that run long may exceed it, or get broken in undesirable ways.
Therefore, when using these three macros, you should preview your
work to ensure that all lines fit as expected.
</p>
</div>

<!-- -BR- -->

<div class="macro-id-overline">
<h3 id="br" class="macro-id">Manually break lines</h3>
</div>

<div class="box-macro-args">
Macro: <b>BR</b>
</div>

<p>
When using
<a href="#justify">JUSTIFY</a>
or
<a href="#quad">QUAD</a>,
BR tells mom about partial lines that you want broken (as opposed to
<a href="definitions.html#filled">filled</a>).
Any partial
<a href="definitions.html#outputline">output line</a>
that immediately precedes BR will be
<a href="definitions.html#quad">quadded</a>
in the direction of the current quad, or set flush left if text is
<a href="definitions.html#just">justified</a>.
</p>

<p>
Most of the time, you won&#8217;t need the BR macro.  In fill modes,
mom tries to be sensible about where breaks are needed.  If the
nature of a macro is such that under most circumstances you&#8217;d
expect a break, mom puts it in herself.  Equally, in macros where a
break isn&#8217;t normally desirable, no break occurs.  This means
text files don&#8217;t get cluttered with annoying BR&#8217;s.
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> Lines of text in
<a href="definitions.html#filled">nofill mode</a>
never require a BR.  Furthermore, in nofill mode, ALL macros cause a
break.  If a break is not desired, use the
<a href="#join"><kbd>\c</kbd></a>
<a href="definitions.html#inlines">inline escape</a>.
</p>

<p class="tip-bottom" style="margin-top: -1em">
<span class="experts">Experts:</span> BR is an alias for
<kbd>.br</kbd>.  You can use either, or mix
&#8217;n&#8217; match with impunity.
</p>
</div>

<!-- -EL- -->

<div class="macro-id-overline">
<h3 id="el" class="macro-id">Manually break a line without advancing on the page</h3>
</div>

<div class="box-macro-args">
Macro: <b>EL</b>
</div>

<p class="requires">
In nofill modes
<span style="font-style: normal;">
(<a href="#left">LEFT</a>,
<a href="#right">RIGHT</a>,
<a href="#center">CENTER</a>)
</span>
you must terminate the line input preceding
<span style="font-style: normal;">EL</span>
with the
<span style="font-style: normal;">
<kbd>\c</kbd> inline escape.
</span>
See
<span style="font-style: normal;">
<a href="#el-notes">NOTES</a>,
</span>
below.
</p>

<p style="margin-top: -.5em">
<i><b>Suggestion:</b> If you find remembering whether to put in the</i>
<kbd>\c</kbd>
<i>bothersome, you may prefer to use the</i>
<a href="definitions.html#inlines">inline escape</a>
<i>alternative to</i> EL,
<a href="inlines.html#b"><kbd>\*[B]</kbd></a>,
<i>which works consistently regardless of the fill mode.
</i>EL <i>does not work after the</i>
<a href="goodies.html#pad">PAD</a>
<i>macro.  See</i>
<a href="goodies.html#nobreak"><kbd>.PAD&nbsp;NOBREAK</kbd></a>
<i>for the way around this.</i>
</p>

<p>
The mnemonic &#8220;EL&#8221; is borrowed from old Compugraphic
typesetting systems, where it stood for
"<span style="text-decoration: underline;">E</span>nd <span style="text-decoration: underline;">L</span>ine."
Conceptually, EL is equivalent to the notion of a carriage return
with no linefeed.
</p>

<p id="el-example">
EL&#8217;s function is simple: it breaks a line without advancing
on the page.  As an example of where you might use it, imagine that
you&#8217;re working from marked-up copy.  The markup indicates 24
points of space between two given lines, but the prevailing line
spacing is 12.5 points.  You may find it more convenient to break
the first line with EL and instruct mom to advance 24 points to the
next line instead of calculating the lead that needs to be added to
12.5 to get 24.  To demonstrate:
<br/>
<span class="pre-in-pp">
  .LEFT
  .LS 12.5
  A line of text.\c
  .EL
  .ALD 24p
  The next line of text.
</span>
may be more intuitive than
<br/>
<span class="pre-in-pp">
  .LEFT
  .LS 12.5
  A line of text.
  .ALD 11.5p
  The next line of text.
</span>
The first example has the further advantage that should you wish to
change the prevailing line space but keep the 24 points lead, you
don&#8217;t have to recalculate the extra space.
</p>

<p>
ALD in the above examples stands for
&#8220;<span style="text-decoration: underline;">A</span>dvance
<span style="text-decoration: underline;">L</span>ea<span style="text-decoration: underline;">D</span>&#8221;
(another mnemonic borrowed from Compugraphic), which is covered in
the section
<a href="#vertical-movements-intro">Vertical movements</a>.
</p>

<div class="box-notes">
<h3 id="el-notes" class="docs notes">Notes</h3>

<p style="margin-top: .5em;">
In versions of mom prior to 1.1.9, EL did not always work as
advertised on the last
<a href="definitions.html#outputline">output line</a>
of pages that contained a footer trap (e.g. one set with
<a href="#b-margin">B_MARGIN</a>
or in  documents formatted using the
<a href="docprocessing.html#docprocessing">document processing macros</a>).
</p>

<p>
EL has been re-written so that this should no longer be the case.
However, in order for it to work in the
<a href="definitions.html#filled">nofill</a>
modes
(<a href="#lrc">LEFT</a>,
<a href="#lrc">RIGHT</a>
or
<a href="#lrc">CENTER</a>),
you must always &#8220;join&#8221; <kbd>.EL</kbd> to
the line before it using the
<kbd><a href="#join">\c</a></kbd>
<a href="definitions.html#inlines">inline escape</a>,
like this:
<br/>
<span class="pre-in-pp">
  .LEFT
  A line I don&#8217;t want to advance\c
  .EL
</span>
Conversely, in
<a href="definitions.html#filled">fill modes</a>
(<a href="#quad">QUAD LEFT</a>,
<a href="#quad">QUAD RIGHT</a>,
<a href="#quad">QUAD CENTER</a>
or
<a href="#justify">JUSTIFY</a>),
the <kbd>\c</kbd> must not be used.
</p>

<p>
If EL is used after most macros or groff
<a href="definitions.html#primitives">primitives</a>
(see the exception, below), you don&#8217;t have to worry about
this, regardless of the fill mode.  Just type
<kbd>.EL</kbd>
</p>

<p class="tip-bottom">
<span class="experts">Experts:</span> EL is unrelated to
groff&#8217;s <kbd>.el</kbd>.  If you find the similarity confusing,
you may want to alias EL as something else (but don&#8217;t use EOL;
mom uses it internally.)
</p>
</div>

<!-- -SP- -->

<div class="macro-id-overline">
<h3 id="space" class="macro-id">Break lines and add space between</h3>
</div>

<div class="box-macro-args">
Macro: <b>SPACE</b> <kbd class="macro-args">&lt;space to add between lines&gt;</kbd>
</div>
<p class="alias">
<i>Alias:</i> <b>SP</b>
</p>

<p>
SPACE breaks a line, just like
<a href="#br">BR</a>,
then adds space after the line.  With no argument, it adds an extra
line space of a value equal to the current
<a href="definitions.html#leading">leading</a>.
If you pass it a numeric argument without supplying a
<a href="definitions.html#unitofmeasure">unit of measure</a>,
it advances that number of extra line spaces.  For example:
<br/>
<span class="pre-in-pp">
  .SPACE
</span>
breaks the line then adds an extra linespace, whereas
<br/>
<span class="pre-in-pp">
  .SPACE 2
</span>
breaks the line and adds two extra linespaces.
</p>

<p>
If you supply a unit of measure, SPACE breaks the line then advances
one linespace (at the current
<a href="definitions.html#leading">leading</a>)
PLUS the specified amount of extra space given to SPACE, as in
<br/>
<span class="pre-in-pp">
  .SPACE 6p
</span>
which breaks the line and advances one full linespace plus six
points.
</p>

<div class="box-tip">
<p class="tip-top">
<span class="tip">Tip:</span> SPACE and
<a href="#ald">ALD</a>
can be used interchangeably (<kbd>.SPACE&nbsp;6p</kbd> and
<kbd>.ALD&nbsp;6p</kbd> are equivalent).  However, ALD without an
argument does nothing, whereas SPACE without an argument adds an
extra line space.  I recommend using SPACE when you want an extra
line space (or multiple thereof), and ALD whenever you want some
other value of space after a line.
</p>

<p class="tip-bottom">
<span class="experts">Experts:</span> SPACE is an alias of
<kbd>.sp</kbd>.  You can use either, or mix &#8217;n&#8217; match
with impunity.
</p>
</div>

<!-- -SPREAD- -->

<div class="macro-id-overline">
<h3 id="spread" class="macro-id">Break and force justify (spread) lines</h3>
</div>

<div class="box-macro-args">
Macro: <b>SPREAD</b>
</div>

<p>
Sometimes, you need to break a line of
<a href="definitions.html#just">justified</a>
text and have it come out fully justified, not
<a href="definitions.html#quad">quadded</a>
left the way it would be with the
<a href="#br">BR</a>
macro.  An example of where you&#8217;d do this would be when you
want to prevent a word at the end of a line from being hyphenated
(say, a proper name). SPREAD is the macro that lets you break the
line and have it came out fully justified.
</p>

<div class="box-tip">
<p class="tip">
<span class="experts">Experts:</span> SPREAD is an alias for
<kbd>.brp</kbd> You can use either, or mix
&#8217;n&#8217; match with impunity.
</p>
</div>

<!-- -JOIN- -->

<div class="macro-id-overline">
<h3 id="join" class="macro-id">Join input lines</h3>
</div>

<div class="box-macro-args">
Inline: <kbd class="macro-args">\c</kbd>
</div>

<p>
Sometimes, especially when in one of the
<a href="definitions.html#filled">nofill modes</a>,
a macro will cause a break where you don&#8217;t want one.  In order
to prevent this from happening (in other words, to join
<a href="definitions.html#inputline">input lines</a>
together, forming one
<a href="definitions.html#outputline">output line</a>),
use the groff
<a href="definitions.html#inlines">inline escape</a>
<kbd>\c</kbd> at the end of each input line to be
joined to another, like this:
<br/>
<span class="pre-in-pp">
  .LEFT
  .FAMILY T
  .FT R
  Some lines of text to be \c
  .FAMILY H
  .FT B
  joined \c
  .FAMILY T
  .FT R
  together.
</span>
Upon output, the lines will be joined together to read
<br/>
<span class="pre-in-pp">
  Some lines of text to be joined together.
</span>
with the word &#8220;joined&#8221; in Helvetica bold.  Note the
spaces before <kbd>\c</kbd>.  Without them, the last three words of
the output line would read
<br/>
<span class="pre-in-pp">
  bejoinedtogether
</span>
Please also note that had the example been in one of the
<a href="definitions.html#filled">fill modes</a>,
there&#8217;d have been no need for the <kbd>\c</kbd>.  
</p>

<div class="box-tip">
<p class="tip">
<b>Addendum:</b> The example, above, is designed to demonstrate the
use of <kbd>\c</kbd>.  An easier and more intuitive way
to accomplish the family/font change in the example would be with
the groff
<a href="definitions.html#inlines">inline escape</a>,
<kbd><a href="inlines.html#inline-fonts-groff">\f</a></kbd>,
like this:
<br/>
<span class="pre-in-pp" style="padding-bottom: 0px;">
  Some lines of text to be \f[HB]joined\*[PREV] together.
</span>
</p>
</div>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="refinements-intro" class="macro-group">Typographic refinements</h2>

<p>
The macros in this section help you tweak groff&#8217;s behaviour,
ensuring that your documents look typographically professional.
</p>

<div id="index-refinements" class="macro-list-container">
<h3 class="macro-list">Typographic refinements macros</h3>

<ul class="macro-list">
  <li>Word and sentence spacing
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#ws">WS</a> &ndash; word spacing</li>
    <li><a href="#ss">SS</a> &ndash; sentence space</li>
  </ul></li>
  <li>Letter spacing (track kerning)
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#rw">RW</a> &ndash; reduce whitespace</li>
    <li><a href="#ew">EW</a> &ndash; expand whitespace</li>
    <li><a href="#br-at-line-kern">BR_AT_LINE_KERN</a></li>
  </ul></li>
  <li>Hyphenation
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#hy">HY</a> &ndash; turn auto hyphenation on/off, or set specific hyphenation parameters</li>
    <li><a href="#hy-set">HY_SET</a> &ndash; set all hyphenation parameters</li>
  </ul></li>
  <li>Automatic kerning and ligatures
  <ul style="list-style-type: none; margin-left: -1em;">
    <li><a href="#kern">KERN</a> &ndash; turn automatic pairwise kerning on or off</li>
    <li><a href="#ligatures">LIGATURES</a> &ndash; turn automatic generation of ligatures on or off</li>
  </ul></li>
</ul>
</div>

<!-- -WS- -->

<div class="macro-id-overline">
<h3 id="ws" class="macro-id">Word spacing</h3>
</div>

<div class="box-macro-args">
Macro: <b>WS</b> <kbd class="macro-args">&lt;+|-wordspace&gt; | DEFAULT</kbd>
</div>

<p>
WS (Word Space) increases or decreases the amount of space between
words.  In
<a href="definitions.html#filled">nofill modes</a>,
or if
<a href="#quad">QUAD</a>
is in effect, the space between words is fixed.  Therefore, if you
change the word spacing with WS, the change applies uniformly to the
space between every word on every line.  However, when text is
<a href="definitions.html#just">justified</a>,
the space between words varies from line to line (in order to
justify the text).  Consequently, the change you make with WS
represents the minimum (and ideal) space groff will try to put
between words before deciding whether to hyphenate a final word or
to stretch the word spacing.
</p>

<p>
Word space is relative to type size.  Knowing how it&#8217;s
calculated is unimportant. What matters is having a sense of how
the value passed to WS affects the look of your type.  Generally,
in/decreasing the word space by a value of 1 or 2 produces a
difference that in many cases is scarcely visible; in/decreasing by
a value of 5 or so produces a subtle but noticeable difference; and
in/decreasing by a value greater than 10 is always apparent.  You
should preview your work to assess the effect of WS.
</p>

<p id="ws-usage">
WS takes as its argument a number (decimal fractions are allowed)
preceded by a plus or minus sign.  Therefore, to decrease the word
space slightly, you might enter <br/>
<span class="pre-in-pp">
  .WS -4
</span>
To increase it by a noticeable amount, you might enter
<br/>
<span class="pre-in-pp">
  .WS +12
</span>
You can reset the word spacing to its previous value by switching
the plus or minus sign, like this:
<br/>
<span class="pre-in-pp">
  .WS +4
  A line of text
  .WS -4
</span>
The <kbd>.WS&nbsp;-4</kbd> undoes the effect of
<kbd>.WS&nbsp;+4</kbd>.  You can also reset WS to its groff default
by entering
<br/>
<span class="pre-in-pp">
  .WS DEFAULT
</span>
This can be particularly useful if you&#8217;ve been playing around
with plus and minus values, and can&#8217;t remember by how much you
have to in/decrease the word space to get it back to normal.
</p>

<!-- -SS- -->

<div class="macro-id-overline">
<h3 id="ss" class="macro-id">Sentence space</h3>
</div>

<div class="box-macro-args">
Macro: <b>SS</b> <kbd class="macro-args">&lt;+sentence space&gt; | 0 | DEFAULT</kbd>
</div>

<p>
SS (Sentence Space) tells groff how to treat double spaces it
encounters between sentences in
<a href="definitions.html#inputline">input lines</a>.
If you use SS, input sentences with two spaces after them <i>and</i>
input sentences that fall at the end of input lines all receive a
normal word space plus an additional amount of space whose size is
determined by the + value passed as an argument to SS.  Thus,
<br/>
<span class="pre-in-pp">
  .SS +2
</span>
means that input sentences with two spaces after them receive a
normal word space PLUS the +2 value passed to SS.
</p>

<p>
Like
<a href="#ws">WS</a>,
increasing the sentence space by a value of 1 or 2 produces a
difference that in many cases is scarcely visible; increasing by a
value of 5 or so produces a subtle but noticeable difference (i.e.
the space between double-spaced input sentences will be slightly but
visibly greater than the space between words); and increasing by a
value greater than 10 is always apparent.  You should preview your
work to assess the effect of SS.
</p>

<p>
There&#8217;s an additional argument you can pass SS: the number
zero (without the + sign).  It&#8217;s the argument you&#8217;ll
use most often.  Typeset copy should never have two spaces between
sentences, and the "zero" argument tells groff to give the extra
spaces no space at all (effectively removing them).  Therefore, if
you double-space your sentences (as you should when writing in a
text editor), get in the habit of putting
<br/>
<span class="pre-in-pp">
  .SS 0
</span>
at the top of your files.
</p>

<p>
If you do use SS for something other than ensuring that you
don&#8217;t get unwanted sentence spaces in output copy, you can set
or reset the sentence space to the groff default (the same width
as a word space, i.e. double-spaced input sentences will appear
double-spaced on output as well) with
<br/>
<span class="pre-in-pp">
  .SS DEFAULT
</span>
If you&#8217;re using the
<a href="docprocessing.html">document processing macros</a>
and your
<a href="docprocessing.html#printstyle">PRINTSTYLE</a>
is <kbd>TYPEWRITE</kbd>, <kbd>.SS&nbsp;DEFAULT</kbd> is the
default, because you do want double spaces between sentences in copy
that imitates the look of a typewritten document.
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> SS with an argument other
than <kbd>0</kbd> (zero) should only be used if you&#8217;re of
the old (and wise) school of typists that puts two spaces between
sentences.  If you ignore this advice and use SS when you habitually
put only one space between sentences, you risk producing output
where the space between sentences is not equal.
</p>
</div>

<!-- -HY- -->

<div class="macro-id-overline">
<h3 id="hy" class="macro-id">Automatic hyphenation control</h3>
</div>

<div class="box-macro-args">
Macro: <b>HY</b> <kbd class="macro-args">LINES &lt;max. number of consecutive hyphenated lines&gt;</kbd>
  <br/>
Macro: <b>HY</b> <kbd class="macro-args">MARGIN &lt;size of hyphenation margin&gt;</kbd>
  <br/>
Macro: <b>HY</b> <kbd class="macro-args">SPACE &lt;extra interword spacing to prevent hyphenation&gt;</kbd>
  <br/>
Macro: <b>HY</b> <kbd class="macro-args">DEFAULT</kbd>
  <br/>
Macro: <b>HY</b> <kbd class="macro-args">toggle</kbd>
</div>
<p class="alias">
<i>Aliases:</i> <b>HYPHENATE, HYPHENATION</b>
</p>

<p>
HY, as you can see, can be invoked with a number of arguments.  In
all cases, the aliases HYPHENATE or HYPHENATION can be used in place
of HY.  To aid in understanding the various arguments you can pass
to HY, I&#8217;ve broken them down into separate sections.
</p>

<h3 class="docs">1.&nbsp;&nbsp;HY</h3>

<p>
HY by itself (i.e. with no argument) simply turns automatic
hyphenation on.  Any argument other than LINES, MARGIN, SPACE or
DEFAULT, turns automatic hyphenation off.  For example, as explained
in
<a href="intro.html#macro-args">How to read macro arguments</a>,
you could turn HY off by entering
<br/>
<span class="pre-in-pp">
  .HY OFF
</span>
or
<span class="pre-in-pp">
  .HY X
</span>
or
<span class="pre-in-pp">
  .HY END
</span>
HY observes the following default hyphenation rules:
</p>
<ul style="margin-top: -.5em; margin-left: 18px;">
  <li>Last lines (i.e. ones that will spring a trap&mdash;typically
      the last line on a page) will not be hyphenated.
  </li>
  <li>The first and last two characters of a word are never
      split off.
  </li>
</ul>

<h3 class="docs numbered">2.&nbsp;&nbsp;HY LINES</h3>

<p>
HY LINES sets the maximum number of consecutive hyphenated lines
that will appear in output copy.  2 is a very good choice, and
you&#8217;d set it with
<br/>
<span class="pre-in-pp">
  .HY LINES 2
</span>
By default, when you turn automatic hyphenation on, there is no
limit to the number of consecutive hyphenated lines.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span>
<a href="definitions.html#discretionaryhyphen">Discretionary hyphens</a>
count when groff is figuring out how many lines to hyphenate;
explicit hyphens do not.
</p>
</div>

<h3 class="docs numbered">3.&nbsp;&nbsp;HY MARGIN</h3>

<p>
HY MARGIN sets the amount of room allowed at the end of a line
before hyphenation is tripped (e.g. if there&#8217;s only 6 points
left at the end of a line, groff won&#8217;t try to hyphenate the
next word).  HY MARGIN only applies if you&#8217;re using
<a href="#quad">QUAD</a>,
and is really only useful if you&#8217;re using QUAD LEFT.
</p>

<p>
As an example, if you don&#8217;t want groff to hyphenate words
when there&#8217;s only 18 points of space left at the end of a
left-quadded line, you&#8217;d enter
<br/>
<span class="pre-in-pp" style="margin-bottom: -1em">
  .HY MARGIN 18p
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> The numeric argument after HY
MARGIN requires a
<a href="definitions.html#unitofmeasure">unit of measure</a>.
</p>
</div>

<h3 class="docs numbered">4.&nbsp;&nbsp;HY SPACE</h3>

<p>
HY SPACE sets an amount of extra interword space that groff will try
to put between words on a line in order to PREVENT hyphenation.  HY
SPACE applies only to
<a href="definitions.html#just">justified lines</a>.
Generally speaking, you&#8217;ll want this value to be quite small,
since too big a value will result in lines with gaping holes between
the words.  A reasonable value might be half a point, or one point,
which you&#8217;d set with
<br/>
<span class="pre-in-pp">
  .HY SPACE .5p
</span>
or
<span class="pre-in-pp" style="margin-bottom: -1em">
  .HY SPACE 1p
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> The numeric argument after HY SPACE
requires a
<a href="definitions.html#unitofmeasure">unit of measure</a>.
</p>
</div>

<h3 class="docs numbered">5.&nbsp;&nbsp;HY DEFAULT</h3>

<p>
HY DEFAULT resets automatic hyphenation to its default behaviour,
cancelling any changes made with HY <kbd>LINES</kbd>, HY
<kbd>MARGIN</kbd>, and/or HY <kbd>SPACE</kbd>.
</p>

<div class="box-notes">
<h3 id="hyphenation-thoughts" class="docs notes">Thoughts on hyphenation in general</h3>

<p style="margin-top: .5em">
Hyphenation is a necessary evil.  If it can be avoided, it
should be.  If it can&#8217;t be, it should occur infrequently.
That&#8217;s the reason for the number of parameters you can set
with HY.
</p>

<p class="tip-bottom">
Furthermore, hyphenation in
<a href="definitions.html#rag">rag</a>
copy requires a great deal of attention.  At best, it should be
avoided completely by individually adjusting the number of words
on consecutive lines to achieve a pleasing, natural-looking rag.
Since such adjustments are often too fussy for document processing,
I recommend playing around with HY MARGIN a bit if your copy looks
hyphen-heavy.
</p>
</div>

<!-- -HY_SET- -->

<div class="macro-id-overline">
<h3 id="hy-set" class="macro-id">Set hyphenation parameters all at once</h3>
</div>

<div class="box-macro-args">
Macro: <b>HY_SET</b> <kbd class="macro-args">&lt;lines&gt; [ &lt;margin&gt; [ &lt;space&gt; ] ]</kbd>
</div>

<p class="alias">
<i>Alias:</i> <b>HYSET</b>
</p>

<p>
HY_SET lets you set the parameters for hyphenation
with a single macro. <kbd>&lt;lines&gt;,</kbd>
<kbd>&lt;margin&gt;</kbd> and
<kbd>&lt;space&gt;</kbd> correspond to the numeric
values required by <kbd>LINES</kbd>,
<kbd>MARGIN</kbd> and <kbd>SPACE</kbd> as described
<a href="#hy">above</a>.
</p>

<p>
To set just the maximum number of consecutive hyphenated lines,
you&#8217;d enter
<br/>
<span class="pre-in-pp">
  .HY_SET 2
</span>
If you wanted the same number of maximum consecutive hyphenated
lines and a hyphenation margin for use with
<a href="definitions.html#rag">rag</a>
copy,
<br/>
<span class="pre-in-pp">
  .HY_SET 2 36p
</span>
would set the hyphenation margin to 36 points.
</p>

<p>
If you wanted the same number of maximum consecutive hyphenated
lines and a hyphenation space of 2 points for use with
<a href="definitions.html#just">justified</a>
copy, 
<br/>
<span class="pre-in-pp">
  .HYSET 2 0 2p
</span>
is how you&#8217;d do it.
</p>

<!-- -RW- -->

<div class="macro-id-overline">
<h3 id="rw" class="macro-id">Reduce whitespace</h3>
</div>

<div class="box-macro-args">
Macro: <b>RW</b> <kbd class="macro-args">&lt;amount of whitespace reduction between letters&gt;</kbd>
</div>

<p>
RW (<span style="text-decoration: underline;">R</span>educe <span style="text-decoration: underline;">W</span>hitespace)
and its corresponding macro,
EW (<span style="text-decoration: underline;">E</span>xpand <span style="text-decoration: underline;">W</span>hitespace),
allow you to tighten (or loosen)
<a href="definitions.html#outputline">output lines</a>
by uniformly reducing or expanding the space between characters.
This is particularly useful when you want to squeeze or stretch
lines on a narrow measure.
</p>

<p>
The value passed to RW may be a whole number or a decimal fraction.
Since a value of 1 produces a noticeable reduction in the space
between letters at text sizes, you&#8217;ll most likely use small
decimal values when tightening lines.  For example,
<br/>
<span class="pre-in-pp">
  .RW .1
</span>
or
<span class="pre-in-pp">
  .RW .2
</span>
may be just enough to squeeze an extra character or two on a line
without the change in letter spacing being obvious.  I highly
recommend previewing your work to assess the effect of RW.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> By default, RW does not deposit a 
<a href="#br">break</a>
when it&#8217;s invoked if you&#8217;re in one of the
<a href="definitions.html#fill">fill</a>
modes (i.e.
<a href="#quad">QUAD</a>
L, R, C, J or
<a href="#justify">JUSTIFY</a>).
If you want
RW to break at the ends of the previous
<a href="definitions.html#inputline">input lines</a>
while you&#8217;re in a fill mode, tell mom
that&#8217;s what you want by invoking
<kbd><a href="#br-at-line-kern">.BR_AT_LINE_KERN</a></kbd>.
</p>
</div>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> In versions prior to
1.1.9-a, RW affected all
<a href="definitions.html#font">fonts</a>
in the
<a href="definitions.html#family">family</a>
current at the time it was invoked.  As of 1.1.9-a, this behaviour
has been changed. RW affects only the font current at the time
it&#8217;s invoked, and remains in effect for that font every time
the font is called, hence must be reset to zero to cancel its effect
(<kbd>.RW&nbsp;0</kbd>) on that font.
</p>
</div>

<!-- -EW- -->

<div class="macro-id-overline">
<h3 id="ew" class="macro-id">Expand whitespace</h3>
</div>

<div class="box-macro-args">
Macro: <b>EW</b> <kbd class="macro-args">&lt;amount of whitespace expansion between letters&gt;</kbd>
</div>

<p>
EW (<span style="text-decoration: underline;">E</span>xpand <span style="text-decoration: underline;">W</span>hitespace)
expands the amount of whitespace between letters, effectively
&#8220;loosening&#8221; lines of type.
</p>

<p>
The value passed to EW may be a whole number or a decimal fraction.
Since a value of 1 produces a noticeable expansion in the space
between letters at text sizes, you&#8217;ll most likely use small
decimal values when loosening lines.  For example,
<br/>
<span class="pre-in-pp">
  .EW .1
</span>
or
<span class="pre-in-pp">
  .EW .2
</span>
may be just enough to open up a line without the change in letter
spacing being obvious.  I highly recommend previewing your work to
assess the effect of EW.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> By default, EW does not deposit a 
<a href="#br">break</a>
when it&#8217;s invoked if you&#8217;re in one of the
<a href="definitions.html#fill">fill</a>
modes (i.e.
<a href="#quad">QUAD</a>
L, R, C, J or
<a href="#justify">JUSTIFY</a>).
If you want
EW to break at the ends of the previous
<a href="definitions.html#inputline">input lines</a>
while you&#8217;re in a fill mode, tell mom that&#8217;s what you
want by invoking the
<kbd><a href="#br-at-line-kern">.BR_AT_LINE_KERN</a></kbd>
toggle macro.
</p>
</div>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> In versions prior to
1.1.9-a, EW affected all
<a href="definitions.html#font">fonts</a>
in the
<a href="definitions.html#family">family</a>
current at the time it was invoked.  As of 1.1.9-a, this behaviour
has been changed.  EW affects only the font current at the time
it&#8217;s invoked, and remains in effect for that font every time
the font is called, hence must be reset to zero to cancel its effect
(<kbd>.EW&nbsp;0</kbd>) on that font.
</p>
</div>

<!-- -BR_AT_LINE_KERN- -->

<div class="macro-id-overline">
<h3 id="br-at-line-kern" class="macro-id">Break before line kerning</h3>
</div>

<div class="box-macro-args">
Macro: <b>BR_AT_LINE_KERN</b> <kbd class="macro-args">toggle</kbd>
</div>

<p>
By default, in
<a href="definitions.html#filled">fill</a>
modes (i.e.
<a href="#quad">QUAD</a>
L, R, C, J or
<a href="#justify">JUSTIFY</a>)
mom does not break
<a href="definitions.html#inputline">input lines</a>
when you invoke
<a href="#rw">RW</a>
or
<a href="#ew">EW</a>.
If you&#8217;d like her to break input lines prior to RW or EW,
invoke <kbd>.BR_AT_INPUT_LINE</kbd> without any argument.  To
disable the breaks, invoke <kbd>.BR_AT_INPUT_LINE</kbd> with any
argument (OFF, QUIT, Q, X...), like this
<br/>
<span class="pre-in-pp">
  .BR_AT_LINE_KERN OFF
</span>
or
<span class="pre-in-pp">
  .BR_AT_LINE_KERN X
</span>
With QUAD L, R or C, mom simply breaks the line.  With QUAD J (or
just JUSTIFY, which is the same thing), she breaks and
<a href="definitions.html#force">force justifies</a>
the line prior to <kbd>.EW</kbd> or <kbd>.RW</kbd>.
</p>

<!-- -KERN- -->

<div class="macro-id-overline">
<h3 id="kern" class="macro-id">Automatic kerning</h3>
</div>

<div class="box-macro-args">
Macro: <b>KERN</b> <kbd class="macro-args">toggle</kbd>
</div>

<p>
By itself (i.e. with no argument), KERN turns automatic pairwise
<a href="definitions.html#kern">kerning</a>
on.  With any argument (e.g. OFF, Q, X), pairwise kerning is turned
off.
</p>

<p>
Kerning of individual character pairs can be controlled with the
<a href="definitions.html#inlines">inline escapes</a>
<kbd>\*[BU &lt;n&gt;]</kbd> and
<kbd>\*[FU &lt;n&gt;]</kbd>.  See
<a href="inlines.html#inline-kerning-mom">Inline Escapes, kerning</a>.
</p>

<!-- -LIGATURES- -->

<div class="macro-id-overline">
<h3 id="ligatures" class="macro-id">Automatic ligature generation</h3>
</div>

<div class="box-macro-args">
Macro: <b>LIGATURES</b> <kbd class="macro-args">toggle</kbd>
</div>
<p class="alias">
<i>Alias:</i> <b>LIG</b>
</p>

<p>
Provided your current font has
<a href="definitions.html#ligatures">ligatures</a>,
LIGATURES, by itself, turns on automatic generation of ligatures.
When automatic ligature generation is on, simply typing the letters
of a ligature combination will produce the correct ligature upon
output.  For example, if you type the word &#8220;finally&#8221;,
the fi combination will be output as an fi ligature.  Generally
speaking, ligatures are A Good Thing, hence mom has them on by
default.
</p>

<p>
LIGATURES with any argument turns automatic ligature generation off.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> Not all fonts support ligatures.
</p>
</div>

<div class="rule-short"><hr/></div>

<!-- ==================================================================== -->

<h2 id="modifications-intro" class="macro-group">Type modifications (pseudo font styles)</h2>

<p>
It sometimes happens that a PostScript 
<a href="definitions.html#family">family</a>
doesn&#8217;t contain all the fonts you need.  You might, for
example, be missing an italic font, or a bold font.  Or you might
not be able to get your hands on a condensed family.  That&#8217;s
where these macros and inline escapes come in.  With them, you
can fake the fonts you&#8217;re missing.  A word of caution,
though: &#8220;faked&#8221; fonts are just that&mdash;faked.  You
should only use them as a last resort, and then only sparingly.  A
word or two or a line or two in a faked font will pass unnoticed;
large patches of type in a faked font look typographically cheap.
</p>

<div id="index-modifications" class="macro-list-container">
<h3 class="macro-list">Type modifications macros</h3>

<ul class="macro-list">
  <li>Pseudo italic
  <ul style="list-style: none; margin-left: -1em;">
    <li><a href="#setslant">SETSLANT</a> &ndash; degree of pseudo-italicizing</li>
    <li><a href="#slant-inline">\*[SLANT]</a> &ndash; inline escape for pseudo-italicizing type</li>
  </ul></li>
  <li>Pseudo bold
  <ul style="list-style: none; margin-left: -1em;">
    <li><a href="#setbolder">SETBOLDER</a> &ndash; amount of emboldening</li>
    <li><a href="#bolder-inline">\*[BOLDER]</a> &ndash; inline escape for emboldening type</li>
  </ul></li>
  <li>Pseudo condensed
  <ul style="list-style: none; margin-left: -1em;">
    <li><a href="#condense">CONDENSE</a> &ndash; percentage for pseudo-condensed type</li>
    <li><a href="#cond-inline">\*[COND]</a> &ndash; inline escape for pseudo-condensed type</li>
  </ul></li>
  <li>Pseudo extended
  <ul style="list-style: none; margin-left: -1em;">
    <li><a href="#extend">EXTEND</a> &ndash; percentage for pseudo-extended type</li>
    <li><a href="#ext-inline">\*[EXT]</a> &ndash; inline escape for pseudo-extending</li>
  </ul></li>
</ul>
</div>

<!-- -SETSLANT- -->

<div class="macro-id-overline">
<h3 id="setslant" class="macro-id">Set degree of slant for pseudo-italicizing</h3>
</div>

<div class="box-macro-args">
Macro: <b>SETSLANT</b> <kbd class="macro-args">&lt;degrees to slant type&gt; | RESET</kbd>
</div>

<p>
Pseudo-italicizing of type is accomplished by slanting a roman font
a certain number of degrees to the right. SETSLANT lets you fix the
number of degrees. Mom&#8217;s default is 15, which produces an
acceptable approximation of an italic font.  If you want another
value&mdash;say, 13 degrees&mdash;you&#8217;d set it by entering
<br/>
<span class="pre-in-pp">
  .SETSLANT 13
</span>
If you change the degree of slant and later want to set it back to
the mom default, do
<br/>
<span class="pre-in-pp">
  .SETSLANT RESET
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> By itself, SETSLANT will not start
pseudo-italicizing type; it merely tells mom what degree of slant
you want.  To start pseudo-italicizing, use the
<a href="definitions.html#inlines">inline escape</a>
<kbd>\*[SLANT]</kbd>.
</p>
</div>

<!-- -\*[SLANT]- -->

<div class="macro-id-overline">
<h3 id="slant-inline" class="macro-id">Pseudo italic on/off</h3>
</div>

<div class="box-macro-args">
Inline: <kbd class="macro-args">\*[SLANT]</kbd>
<br/>
Inline: <kbd class="macro-args">\*[SLANTX</kbd>]
</div>

<p>
<kbd class="macro-args">\*[SLANT]</kbd> begins pseudo-italicizing type.
<kbd class="macro-args">\*[SLANTX]</kbd> turns the feature off.  Both are
<a href="definitions.html#inlines">inline escapes</a>,
therefore they should not appear as separate lines, but rather be
embedded in text lines, like this:
<br/>
<span class="pre-in-pp">
  Not \*[SLANT]everything\*[SLANTX] is as it seems.
</span>
Alternatively, if you wanted the whole line pseudo-italicized,
you&#8217;d do
<br/>
<span class="pre-in-pp">
  \*[SLANT]Not everything is as it seems.\*[SLANTX]
</span>
Once <kbd>\*[SLANT]</kbd> is invoked, it remains in effect until
turned off.
</p>

<div class="box-tip" style="margin-top: .5em;">
<p class="tip">
<span class="note">Note:</span> If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>
with
<a href="docprocessing.html#printstyle">PRINTSTYLE TYPEWRITE</a>,
mom underlines pseudo-italics by default.  To change this behaviour,
use the special macro
<a href="docprocessing.html#typewrite-control">SLANT_MEANS_SLANT</a>.
</p>
</div>

<!-- -SETBOLDER- -->

<div class="macro-id-overline">
<h3 id="setbolder" class="macro-id">Set amount of emboldening</h3>
</div>

<div class="box-macro-args">
Macro: <b>SETBOLDER</b> <kbd class="macro-args">&lt;amount of emboldening, in machine units&gt; | RESET</kbd>
</div>

<p>
Emboldening of type is accomplished by printing characters twice;
the second printing is slightly offset from the first, effectively
&#8220;thickening&#8221; the character.  SETBOLDER lets you set the
number of
<a href="definitions.html#units">machine units</a>
for the offset.  Mom&#8217;s default is 700 units, which produces an
acceptable approximation of a bold font.  If you want another
value&mdash;say, 500 units&mdash;you&#8217;d set it by entering
<br/>
<span class="pre-in-pp">
  .SETBOLDER 500
</span>
If you change the emboldening offset and later want to set it back
to the mom default, do
<br/>
<span class="pre-in-pp">
  .SETBOLDER RESET
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> By itself, SETBOLDER will not start
emboldening type; it merely tells mom what you want the emboldening
offset to be.  To start emboldening, use the
<a href="definitions.html#inlines">inline escape</a>
<kbd>\*[BOLDER]</kbd>.
</p>
</div>

<!-- -\*[BOLDER]- -->

<div class="macro-id-overline">
<h3 id="bolder-inline" class="macro-id">Emboldening on/off</h3>
</div>

<div class="box-macro-args">
Inline: <kbd class="macro-args">\*[BOLDER]</kbd>
<br/>
Inline: <kbd class="macro-args">\*[BOLDERX]</kbd>
</div>

<p>
<kbd class="macro-args">\*[BOLDER]</kbd> begins emboldening type.
<kbd class="macro-args">\*[BOLDERX]</kbd> turns the feature off.  Both are
<a href="definitions.html#inlines">inline escapes</a>,
therefore they should not appear as separate lines, but rather be
embedded in text lines, like this:
<br/>
<span class="pre-in-pp">
  Not \*[BOLDER]everything\*[BOLDERX] is as it seems.
</span>
Alternatively, if you wanted the whole line emboldened,
you&#8217;d do
<br/>
<span class="pre-in-pp">
  \*[BOLDER]Not everything is as it seems.\*[BOLDERX]
</span>
Once <kbd>\*[BOLDER]</kbd> is invoked, it remains in effect
until turned off.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>
with
<a href="docprocessing.html#printstyle">PRINTSTYLE TYPEWRITE</a>,
mom ignores <kbd>\*[BOLDER]</kbd> requests.
</p>
</div>

<!-- -CONDENSE- -->

<div class="macro-id-overline">
<h3 id="condense" class="macro-id">Set percentage for pseudo-condensed type</h3>
</div>

<div class="box-macro-args">
Macro: <b>CONDENSE</b> <kbd class="macro-args">&lt;pseudo-condense percentage&gt;</kbd>
</div>

<p>
Pseudo-condensing of type is accomplished by reducing the width of
characters at a given point size without reducing their height,
effectively narrowing them so they look like condensed type.
CONDENSE tells mom what percentage of the normal character width you
want the characters to be condensed.
</p>

<p>
Mom has no default value for CONDENSE, therefore you must set it
before using the
<a href="definitions.html#inlines">inline escape</a>
<kbd><a href="#cond-inline">\*[COND]</a></kbd>.
80 percent of the normal character width is a good value, and
you&#8217;d set it like this:
<br/>
<span class="pre-in-pp">
  .CONDENSE 80
</span>
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> By itself, CONDENSE will not start
pseudo-condensing type; it merely tells mom what percentage of the
normal character width you want characters to be condensed.  To
start pseudo-condensing, use the
<a href="definitions.html#inlines">inline escape</a>
<kbd>\*[COND]</kbd>.
</p>

<p class="tip-bottom">
<span class="additional-note">Additional note:</span> Make sure that
pseudo-condensing is off (with
<kbd><a href="#cond-inline">\*[CONDX]</a></kbd>)
before before making any changes to the pseudo-condense percentage
with CONDENSE.
</p>
</div>

<!-- -\*[COND]- -->

<div class="macro-id-overline">
<h3 id="cond-inline" class="macro-id">Pseudo-condensing on/off</h3>
</div>

<div class="box-macro-args">
Inline: <kbd class="macro-args">\*[COND]</kbd>
<br/>
Inline: <kbd class="macro-args">\*[CONDX]</kbd>
</div>

<p>
<kbd>\*[COND]</kbd> begins pseudo-condensing type.
<kbd>\*[CONDX]</kbd> turns the feature off.  Both are
<a href="definitions.html#inlines">inline escapes</a>,
therefore they should not appear as separate lines, but rather be
embedded in text lines, like this:
<br/>
<span class="pre-in-pp">
  \*[COND]Not everything is as it seems.\*[CONDX]
</span>
<kbd>\*[COND]</kbd> remains in effect until you turn it
off with <kbd>\*[CONDX]</kbd>.
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> You must turn
<kbd>\*[COND]</kbd>
off before making any changes to the point size of your type, either
via the
<a href="#ps">PT_SIZE</a>
macro or with the <kbd>\s</kbd> inline escape.  If you wish
the new point size to be pseudo-condensed, simply reinvoke
<kbd>\*[COND]</kbd> afterwards.  Equally, <kbd>\*[COND]</kbd> must
be turned off before changing the condense percentage with
<kbd><a href="#condense">.CONDENSE</a></kbd>.
</p>
</div>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>
with
<a href="docprocessing.html#printstyle">PRINTSTYLE TYPEWRITE</a>,
mom ignores <kbd>\*[COND]</kbd> requests.
</p>
</div>

<!-- -EXTEND- -->

<div class="macro-id-overline">
<h3 id="extend" class="macro-id">Set percentage for pseudo-extended type</h3>
</div>

<div class="box-macro-args">
Macro: <b>EXTEND</b> <kbd class="macro-args">&lt;pseudo-extend percentage&gt;</kbd>
</div>

<p>
Pseudo-extending of type is accomplished by increasing the width of
characters at a given point size without increasing their height,
effectively widening them so they look like extended type. EXTEND
tells mom what percentage of the normal character width you want the
characters to be extended.
</p>

<p>
Mom has no default value for EXTEND, therefore you must set it
before using the
<a href="definitions.html#inlines">inline escape</a>
<kbd><a href="#ext-inline">\*[EXT]</a></kbd>.
120% of the normal character width is a good value, and you&#8217;d
set it like this:
<br/>
<span class="pre-in-pp">
  .EXTEND 120
</span>
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> By itself, EXTEND will not start
pseudo-extending type; it merely tells mom what percentage of the
normal character width you want characters to be extended.  To start
pseudo-extending, use the
<a href="definitions.html#inlines">inline escape</a>
<kbd>\*[EXT]</kbd>.
</p>

<p class="tip-bottom">
<span class="additional-note">Additional note:</span> Make sure that
pseudo-extending is off (with
<a href="#ext-inline"><kbd>\*[EXTX]</kbd></a>)
before before making any changes to the pseudo-extend percentage
with EXTEND.
</p>
</div>

<!-- -\*[EXT]- -->

<div class="macro-id-overline">
<h3 id="ext-inline" class="macro-id">Pseudo-extending on/off</h3>
</div>

<div class="box-macro-args">
Inline: <kbd class="macro-args">\*[EXT]</kbd>
<br/>
Inline: <kbd class="macro-args">\*[EXTX]</kbd>
</div>

<p>
<kbd>\*[EXT]</kbd> begins pseudo-extending type.
<kbd>\*[EXTX]</kbd> turns the feature off.  Both are
<a href="definitions.html#inlines">inline escapes</a>,
therefore they should not appear as separate lines, but rather be
embedded in text lines, like this:
<br/>
<span class="pre-in-pp">
  \*[EXT]Not everything is as it seems.\*[EXTX]
</span>
<kbd>\*[EXT]</kbd> remains in effect until you turn it off with
<kbd>\*[EXTX]</kbd>.
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> You must turn
<kbd>\*[EXT]</kbd> off before making any changes to the point size
of your type, either via the
<a href="#ps">PT_SIZE</a>
macro or with the <kbd>\s</kbd> inline escape.  If you wish the new
point size to be pseudo-extended, simply reinvoke <kbd>\*[EXT]</kbd>
afterwards.  Equally, <kbd>\*[EXT]</kbd> must be turned off before
changing the extend percentage with
<a href="#extend">EXTEND</a>.
</p>
</div>
<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> If you&#8217;re using the
<a href="docprocessing.html#docprocessing">document processing macros</a>
with
<a href="docprocessing.html#printstyle">PRINTSTYLE TYPEWRITE</a>,
mom ignores <kbd>\*[EXT]</kbd> requests.
</p>
</div>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="aldrld-intro" class="macro-group">Vertical movements</h2>

The two macros in this section allow you to move down or up on the
page relative to the current
<a href="definitions.html#baseline">baseline</a>.

<div id="index-aldrld" class="macro-list-container">
<h3 class="macro-list">Vertical movements macros</h3>
<ul class="macro-list">
  <li><a href="#ald">ALD</a> &ndash; Advance Lead</li>
  <li><a href="#rld">RLD</a> &ndash; Reverse Lead</li>
</ul>
</div>

<!-- -ALD- -->

<div class="macro-id-overline">
<h3 id="ald" class="macro-id">Advance Lead (move downward)</h3>
</div>

<div class="box-macro-args">
Macro: <b>ALD</b> <kbd class="macro-args">&lt;distance to move downward&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
ALD takes one argument: the distance to move downward on the page
relative to the current vertical position.
</p>

<p>
Used by itself, or preceded by
<a href="#br">BR</a>,
ALD will advance by one line space plus the distance you specify.
Preceded by
<a href="#el">EL</a>,
it will advance by exactly the distance you specify.
</p>

<p>
ALD requires a unit of measure.  Decimal fractions are allowed, and
values may be combined.  Therefore, to move down on the page by 1/4
of an inch, you could enter either
<br/>
<span class="pre-in-pp">
  .ALD .25i
</span>
or
<br/>
<span class="pre-in-pp">
  .ALD 1P+6p
</span>
As the mnemonic
(<span style="text-decoration: underline;">A</span>dvance <span style="text-decoration: underline;">L</span>ea<span style="text-decoration: underline;">D</span>)
suggests, you&#8217;ll most often use ALD with
<a href="definitions.html#picaspoints">points</a>
of lead.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> if you want to use ALD at the top
of a page (i.e. to advance to the starting position of type on a
page), combine the value you want with <kbd>-1v</kbd> (minus one
line space), like this:
<br/>
<span class="pre-in-pp">
  .ALD 1i-1v
</span>
At the top of a page, this will advance one inch from the top edge
of the paper.  Without the -1v, the same command would advance one
inch from the top of the page plus the distance of one line space.
</p>
</div>

<!-- -RLD- -->

<div class="macro-id-overline">
<h3 id="rld" class="macro-id">Reverse Lead (move upward)</h3>
</div>

<div class="box-macro-args">
Macro: <b>RLD</b> <kbd class="macro-args">&lt;distance to move upward&gt;</kbd>
</div>
<p class="requires">
&bull;&nbsp;Requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
RLD takes one argument: the distance to move upward on the page
relative to the current vertical position.
</p>

<p>
Used by itself, or preceded by
<a href="#br">BR</a>,
RLD will advance by one line space, then reverse by the distance you
specify.  Preceded by
<a href="#el">EL</a>,
it will reverse by exactly the distance you specify.
</p>

<p>
RLD requires a unit of measure.  Decimal fractions are allowed, and
values may be combined.  Therefore, to move up on the page by 1/4 of
an inch, you could enter either
<br/>
<span class="pre-in-pp">
  .RLD .25i
</span>
or
<span class="pre-in-pp">
  .RLD 1P+6p
</span>
As the mnemonic
(<span style="text-decoration: underline;">R</span>everse <span style="text-decoration: underline;">L</span>ea<span style="text-decoration: underline;">D</span>)
suggests, you&#8217;ll most often use RLD with
<a href="definitions.html#picaspoints">points</a>
of lead.
</p>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="tabs-intro" class="macro-group">Tabs</h2>

<p>
Mom provides two different kinds of tab setup: typesetting tabs
and string tabs.  Neither one has anything to do with the tab key
on your keyboard, and both are utterly divorced from groff&#8217;s
notion of tabs.  I recommend reading this section carefully in order
to understand how mom handles tabs.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> see the section
<a href="docprocessing.html#behaviour">Typesetting macros during document processing</a>
for re-assuring information on the use of tabs during
<a href="docprocessing.html#docprocessing">document processing</a>.
</p>
</div>

<h3 id="typesetting-tabs" class="docs">Typesetting tabs</h3>

<p>
Typesetting tabs are defined by both an indent from the left margin
and a line length.  This is quite different from typewriter-style
tab stops (the groff norm) that only define the left indent.  In
conjunction with the
<a href="#multicolumns-intro">multi-column macros</a>,
typesetting tabs significantly facilitate tabular and columnar work.
</p>

<p>
Typesetting tabs are created with the
<a href="#tab-set">TAB_SET</a>
macro. TAB_SET identifies the tab (by number), establishes its left
indent and line length, and optionally sets a quad direction and
fill mode.  After tabs have been created with TAB_SET, they can be
called at any time with the
<a href="#tab">TAB</a>
macro.
</p>

<div class="examples-container">
<h3 id="typesetting-tabs-tut" class="docs notes">Quickie tutorial on typesetting tabs</h3>

<p style="margin-top: .5em;">
Say you want to set up three tabs to produce an employee evaluation
that looks something like this:
</p>

<div class="box-code" style="padding-bottom: 0;">
<span id="typsetting-tabs-sample" class="pre-in-pp" style="color: #302419">
CRITERION       EVALUATION     COMMENTS

Service           Good         Many clients specifically request
                               support from Joe by name.

Punctuality    Satisfactory    Tends to arrive after 8:00am, but
                               often works through lunch hour.

Team spirit     Needs work     Persistently gives higher priority
                               to helping clients than respecting
                               organizational hierarchy.
</span>
</div>

<p>
You want the first tab, CRITERION,
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>to begin at the left margin of the page &ndash; i.e. no indent</li>
<li>to have a line length of 5 picas</li>
<li>to be set flush left</li>
</ul>

<p>
Tabs must be numbered, and each has to be set up with a separate
<a href="#tab-set">TAB_SET</a>
line.  Therefore, to set up tab 1, you enter
<br/>
<span class="pre-in-pp">
  .TAB_SET  1  0  5P  L
            |  |  |   |
     tab #--+  |  |   +--direction
               |  |
       indent--+  +--length
</span>
You want the second tab, EVALUATION,
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>to begin 8 picas from the left margin</li>
<li>to have a length of 9 picas</li>
<li>to be set centered</li>
</ul>

<p>
You set it up like this:
<br/>
<span class="pre-in-pp">
  .TAB_SET  2  8P  9P  C
            |  |   |   |
     tab #--+  |   |   +--direction
               |   |
       indent--+   +--length
</span>
You want the third tab, COMMENTS,
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>to begin 19 picas from the left margin</li>
<li>to have a length of 17 picas</li>
<li>to be set flush left, <a href="definitions.html#filled">filled</a></li>
</ul>

<p>
The setup looks like this:
<br/>
<span class="pre-in-pp">
  .TAB_SET  3  19P  17P  L  QUAD
            |   |    |   |    |
            |   |    |   |    +--fill output lines
            |   |    |   |
     tab #--+   |    |   +--direction
                |    |
        indent--+    +--length
</span>
Once the tabs are set up, you can call them in one of two ways:
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>with <kbd><a href="#tab">.TAB</a></kbd> (passing the tab
    number as an argument), which breaks the current line,
    advances one linespace and calls the tab.</li>
<li>with <kbd><a href="#tn">.TN</a></kbd> (Tab Next), which keeps
    you on the current line and moves over to the next
    tab in sequence (i.e. from 1 to 2, 2 to 3, etc.).</li>
</ul>

<p>
To exit from tabs and restore your original left margin, line
length, quad direction and fill mode, use
<kbd><a href="#tq">.TQ</a></kbd>
(Tab Quit).
</p>

<p>
Here&#8217;s how the input for our sample employee evaluation looks
(with some introductory parameters):
</p>

<div class="examples" style="margin-bottom: 0px;">Code:</div>
<div class="box-code" style="height: 324px; padding-bottom: 18px; overflow: auto;">
<span class="pre-in-pp">
.PAGE 8.5i 11i 1i 1i 1i
.FAMILY  T
.FT      R
.PT_SIZE 14
.LS      16
.QUAD    LEFT
.KERN
.HY OFF
.SS 0
.TAB_SET 1 0   5P  L
.TAB_SET 2 8P  9P  C
.TAB_SET 3 19P 17P L QUAD
.TAB 1
CRITERION
.TN
EVALUATION
.TN
COMMENTS
.SP
.TAB 1
Service
.TN
Good
.TN
Many clients specifically request support from Joe by name.
.SP
.TAB 1
Punctuality
.TN
Satisfactory
.TN
Tends to arrive after 8:00am, but often works through lunch hour.
.SP
.TAB 1
Team spirit
.TN
Needs work
.TN
Persistently gives higher priority to helping clients
than respecting organizational hierarchy.
.TQ
</span>
</div>

<p>
Try setting this up and processing it it with
<br/>
<span class="pre-in-pp">
  groff -mom &lt;filename&gt; &gt; &lt;filename&gt;.ps
</span>
then previewing the .ps file.  Notice how <kbd>.TN</kbd>
simply moves over to the next tab, while the combination
<kbd>.SP/.TAB&nbsp;1</kbd> breaks the line, advances by one extra
linespace, and calls the first tab.
</p>

<p>
Notice, too, how the <kbd>QUAD</kbd> argument passed to tab 3 means
you don&#8217;t have to worry about the length of
<a href="definitions.html#inputline">input lines</a>;
mom
<a href="definitions.html#filled">fills</a>
the tab and sets the type flush left.
</p>
</div>

<h3 id="string-tabs" class="docs">String tabs (autotabs)</h3>

<p>
String tabs let you mark off tab positions with
<a href="definitions.html#inlines">inline escapes</a>
embedded in
<a href="definitions.html#inputline">input lines</a>.
Left indents and line lengths are calculated from the beginning and
end positions of the marks.  This is especially useful when tab
indents and lengths need to be determined from the text that goes in
each tab.
</p>

<p>
Setting up string tabs is a two-step procedure.  First, you enter an
input line in which you mark off where you want tabs to begin and
end.  (This is often best done in conjunction with the
<a href="goodies.html#silent">SILENT</a>
macro.)
</p>

<p>
Next, you invoke the
<a href="#st">ST</a>
macro for every string tab you defined, and optionally pass quad and
fill information to it.  That done, string tabs are called with the
<a href="#tab">TAB</a>
macro, just like typesetting tabs.
</p>

<p>
In combination with the
<a href="goodies.html#pad">PAD</a>
macro and the groff inline escape
<kbd><a href="inlines.html#inline-horizontal-groff">\h</a></kbd>
(move horizontally across the page) or mom&#8217;s
<kbd><a href="inlines.html#inline-horizontal-mom">\*[FWD &lt;distance&gt;]</a></kbd>
(move forward) inline, string tabs provide tremendous flexibility in
setting up complex tab structures.
</p>

<div class="examples-container">
<h3 id="string-tabs-tut" class="docs notes">Quickie tutorial on string tabs</h3>
<p style="margin-top: .5em;">
Say you want to set up tabs for the
<a href="#typsetting-tabs-sample">employee evaluation form</a>
used as an example in the
<a href="#typesetting-tabs-tut">typesetting tabs tutorial</a>.
This time, though, you want to play around with the point size of
type, so you can&#8217;t know exactly how long the tabs will be or
where they should start.  All you know is
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>CRITERION is the longest line in tab 1</li>
<li>EVALUATION is the longest line in tab 2</li>
<li>tab 3 should extend to the current right margin</li>
<li>you want a 1 pica gutter between each tab</li>
</ul>

<p>
This is an ideal job for string tabs.
</p>

<p>
The first thing you need for string tabs is an
<a href="definitions.html#inputline">input line</a>
with tab positions marked on it.  Tabs are marked with the
<a href="definitions.html#inlines">inline escapes</a>
<kbd><a href="#inline-st">\*[ST&lt;n&gt;]</a></kbd>
and
<kbd><a href="#inline-st">\*[ST&lt;n&gt;X]</a></kbd>,
where <kbd>&lt;n&gt;</kbd>
is the number you want the tab to have.  (In this example, we
enclose the input line with the
<a href="goodies.html#silent">SILENT</a>
macro so the line doesn&#8217;t print.  We also use the
<a href="goodies.html#pad">PAD</a>
macro to permit defining tab 3 as simply &#8220;the amount of space
remaining on the input line.&#8221;)
</p>

<p>
The setup looks like this:
</p>

<div class="examples" style="margin-bottom: 0px;">Code:</div>

<div class="box-code">
<span class="pre-in-pp">
.SILENT
.PAD "\*[ST1]CRITERION\*[ST1X]\*[FWD 12p]\*[ST2]EVALUATION\*[ST2X]\*[FWD 12p]\*[ST3]#\*[ST3X]"
.SILENT OFF
</span>
</div>

<p>
The long line after <kbd>.PAD</kbd> looks scary, but
it isn&#8217;t really.  Here&#8217;s what it means when broken down
into its component parts:
</p>
<ul style="margin-bottom: -1em;">
<li>The longest line in tab 1 is &#8220;CRITERION&#8221;, so we
    enclose CRITERION with begin/end markers for string tab 1:
<br/>
<span class="pre-in-pp" style="margin-bottom: -.25em;">
  \*[ST1]CRITERION\*[ST1X]
</span>
</li>
<li>We want a 1 pica (12 points) gutter between tab 1 and 2,
    so we insert 12 points of space with \*[FWD 12p]
    (ForWarD 12 points):
<br/>
<span class="pre-in-pp" style="margin-bottom: -.25em;">
  \*[FWD 12p]
</span>
</li>
<li>The longest line in tab 2 is &#8220;EVALUATION&#8221;, so
    we enclose EVALUATION with begin/end markers for string
    tab 2:
<span class="pre-in-pp" style="margin-bottom: -.25em;">
  \*[ST2]EVALUATION\*[ST2X]
</span>
</li>
<li>We want 1 pica (12 points) between tab 2 and 3, so we
    insert it with: 
<br/>
<span class="pre-in-pp" style="margin-bottom: -.25em;">
  \*[FWD 12p]
</span>
</li>
<li>We want tab 3 to be as long as whatever space remains on
    the current line length, so we enclose the
    <a href="goodies.html#pad-marker">pad marker</a>
    (#) with begin/end markers for string tab 3:
<span class="pre-in-pp">
  \*[ST3]#\*[ST3X]
</span>
   </li>
</ul>

<p>
The tabs are now defined, but they require
<a href="definitions.html#quad">quad direction</a>
and
<a href="definitions.html#filled">fill</a>
information.  For each string tab defined above, enter a separate
<kbd><a href="#st">.ST</a></kbd>
line, like this:
<br/>
<span class="pre-in-pp">
  .ST  1  L
  .ST  2  L
  .ST  3  L  QUAD
       |  |   |
       |  |   +--fill output lines
       |  |
  tab #--+  +--direction
</span>
From here on in, you call the tabs with
<kbd><a href="#tab">.TAB</a></kbd>
and
<kbd><a href="#tn">.TN</a></kbd>
just like typesetting tabs (see
<a href="#typesetting-tabs-tut">typesetting tabs tutorial</a>).
</p>

<p>
Here&#8217;s the complete setup and entry for the sample employee
evaluation form utilizing string tabs.
</p>

<div class="examples" style="margin-bottom: 0px;">Code:</div> 
<div class="box-code" style="height: 324px; padding-bottom: 18px; overflow: scroll;">
<span class="pre-in-pp">
.PAGE 8.5i 11i 1i 1i 1i
.FAMILY  T
.FT      R
.PT_SIZE 14
.LS      16
.QUAD    LEFT
.KERN
.HY OFF
.SS 0
.SILENT
.PAD "\*[ST1]CRITERION\*[ST1X]\*[FWD 12p]\*[ST2]EVALUATION\*[ST2X]\*[FWD 12p]\*[ST3]#\*[ST3X]"
.SILENT OFF
.ST  1  L
.ST  2  L
.ST  3  L  QUAD
.TAB 1
CRITERION
.TN
EVALUATION
.TN
COMMENTS
.SP
.TAB 1
Service
.TN
Good
.TN
Many clients specifically request support from Joe by name.
.SP
.TAB 1
Punctuality
.TN
Satisfactory
.TN
Tends to arrive after 8:00am, but often works through lunch hour.
.SP
.TAB 1
Team spirit
.TN
Needs work
.TN
Persistently gives higher priority to helping clients
than respecting organizational hierarchy.
.TQ
</span>
</div>

<p>
Try setting this up and processing it with
<br/>
<span class="pre-in-pp">
  groff -mom &lt;filename&gt; &gt; &lt;filename&gt;.ps 
</span>
and previewing the .ps file.
</p>

<p>
Now, change the point size of the above sample to 12 and preview it
again.  You&#8217;ll see that the tab structure remains identical
(tab 1=CRITERION, tab 2=EVALUATION, tab 3=space remaining, and the
gutter between tabs is still 1 pica), while the position and length
of the tabs have altered because of the new point size.
</p>

<p>
Now try increasing the gutters to 2 picas
(<kbd>\*[FWD&nbsp;24p]</kbd> or <kbd>\*[FWD&nbsp;2P]</kbd> instead
of <kbd>\*[FWD&nbsp;12p]</kbd>).  Preview the file again, and notice
how the tab structure remains the same, but the gutters are wider.
</p>
</div>

<div id="index-tabs" class="macro-list-container">
<h3 class="macro-list">Tabs macros</h3>

<ul class="macro-list">
  <li><a href="#tab-set">TAB_SET</a> &ndash; create typesetting tabs</li>
  <li><a href="#inline-st">\*[ST]...\*[STX]</a> &ndash; inline escapes for marking String Tabs</li>
  <li><a href="#st">ST</a> &ndash; set String Tabs</li>
  <li><a href="#tab">TAB</a> &ndash; call tabs</li>
  <li><a href="#tn">TN</a> &ndash; Tab Next; call next tab in a sequence</li>
  <li><a href="#tq">TQ</a> &ndash; Tab Quit</li>
</ul>

</div>

<!-- -TAB_SET- -->

<div class="macro-id-overline">
<h3 id="tab-set" class="macro-id">Set up typesetting tabs</h3>
</div>

<div class="box-macro-args">
Macro: <b>TAB_SET</b> <kbd class="macro-args">&lt;tab number&gt; &lt;indent&gt; &lt;length&gt;  L | R | C | J [ QUAD ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;<kbd style="font-style: normal;">&lt;indent&gt;</kbd> and <kbd style="font-style: normal;">&lt;length&gt;</kbd> require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p style="margin-bottom: -.5em;">
TAB_SET creates typesetting tabs that later can be called with
<kbd><a href="#tab">.TAB</a></kbd>.
Typesetting tabs are numbered, and defined by an indent, a length,
and a quad direction, hence TAB_SET has four required arguments:
</p>
<ul style="margin-top: .5em; margin-bottom: -.5em;">
<li>a tab number</li>
<li>an indent (measured from the left margin of the page,
    or, if you&#8217;re already in a tab, from the left margin of the tab)</li>
<li>a length</li>
<li>a direction</li>
</ul>

<p>
To set up a centred tab 6 picas long and 9 points from the left
margin, you&#8217;d enter
<br/>
<span class="pre-in-pp">
  .TAB_SET 1 9p 6P C
</span>
The tab number in the above (&#8221;1&#8221;) is simply an
identifier.  It could have been 4, or 17, or 296.  There&#8217;s no
need to set up tabs in numerical sequence.
</p>

<p>
By default, tabs are in
<a href="definitions.html#filled">nofill</a>
mode, meaning you can enter text in tabs on a line-for-line basis
without having to use the
<a href="#br">BR</a>
macro.  If you want a tab to be
<a href="definitions.html#filled">filled</a>,
pass the optional argument <kbd>QUAD</kbd>,
which will make the tab behave as if you&#8217;d entered
<kbd class="bold">.QUAD&nbsp;L&nbsp;|&nbsp;R&nbsp;|&nbsp;C</kbd>.
</p>

<p>
For
<a href="definitions.html#just">justified</a>
tabs, simply pass the argument J (without the QUAD argument), like
this:
<br/>
<span class="pre-in-pp">
  .TAB 1 9p 6P J
</span>
Once tabs are set, they can be called at any time with the
<a href="#tab">TAB &lt;n&gt;</a>
macro, where &lt;n&gt; is the number of the desired tab.
</p>

<p>
You can set up any number of typesetting tabs.  However, be aware
that
<a href="#string-tabs">string tabs</a>
are also called with TAB &lt;n&gt;, so be careful that you
don&#8217;t set up a typesetting tab numbered, say, 4, when you
already have a string tab numbered 4.  Every tab, typesetting or
string, must have a unique numeric identifier. </p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> If you use TAB_SET while
you&#8217;re currently inside a tab, the indent argument is the
distance from the tab&#8217;s left margin, not the left margin of
the page.  Therefore, you should exit tabs (with
<kbd><a href="#tq">.TQ</a></kbd>)
before creating new tabs (unless, of course, you want to set up a
tab structure within the confines of an existing tab).
</p>
</div>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> Turn all indents off (see
<a href="#indents">Indents</a>)
before setting up tabs with TAB_SET, or mom may get confused.
</p>
</div>

<!-- -INLINE_ST- -->

<div class="macro-id-overline">
<h3 id="inline-st" class="macro-id">Mark positions of string tabs</h3>
</div>

<div class="box-macro-args">
Inlines: <kbd class="macro-args">\*[ST&lt;number&gt;]...\*[ST&lt;number&gt;X]</kbd>
</div>

<p class="requires">
The <a href="definitions.html#quad">quad</a>
direction must be
<span style="font-style: normal">LEFT</span>
or
<span style="font-style: normal">JUSTIFY</span>
(see
<a href="#quad"><span style="font-style: normal">QUAD</span></a>
and
<a href="#justify"><span style="font-style: normal">JUSTIFY</span></a>)
or the
<a href="definitions.html#filled">no-fill mode</a>
set to
<a href="#lrc"><span style="font-style: normal">LEFT</span></a>
in order for these inlines to function properly.  Please see
<a href="#important"><span style="font-style: normal">IMPORTANT</span></a>,
below.
</p>

<p>
String tabs need to be marked off with
<a href="definitions.html#inlines">inline escapes</a>
before being set up with the
<a href="#st">ST</a>
macro.  Any input line may contain string tab markers. <kbd
class="bold">&lt;number&gt;</kbd>, above, means the numeric
identifier of the tab.  The following shows a sample input line with
string tab markers.
<br/>
<span class="pre-in-pp">
  \*[ST1]Now is the time\*[ST1X] for all \*[ST2]good men\*ST2X] to come to the aid of the party.
</span>
String tab 1 begins at the start of the line and ends after the word
&#8220;time&#8221;.  String tab 2 starts at &#8220;good&#8221; and
ends after &#8220;men&#8221;.  Inline escapes (e.g. font or point
size changes, or horizontal movements, including
<a href="goodies.html#pad">padding</a>)
are taken into account when mom determines the position and length
of string tabs.
</p>

<p>
Up to nineteen string tabs may be marked (not necessarily all on the
same line, of course), and they must be numbered between 1 and 19.
</p>

<p>
Once string tabs have been marked in input lines, they have to be
&#8220;set&#8221; with
<kbd><a href="#st">.ST</a></kbd>,
after which they may be called, by number, with
<kbd><a href="#tab">.TAB</a></kbd>.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> Lines with string tabs marked off
in them are normal input lines, i.e. they get printed, just like
any input line.  If you want to set up string tabs without the line
printing, use the
<a href="goodies.html#silent">SILENT</a>
macro.
</p>
</div>

<div class="box-important">
<p class="tip-top">
<span id="important" class="important">IMPORTANT:</span>
Owing to the way groff processes
<a href="definitions.html#inputline">input lines</a>
and turns them into
<a href="definitions.html#outputline">output lines</a>,
it is not possible for mom to &#8220;guess&#8221; the correct
starting position of string tabs marked off in lines that are
centered or set flush right.
</p>

<p>
Equally, she cannot guess the starting position if a line is fully
justified and broken with
<a href="#spread">SPREAD</a>.
</p>

<p>
In other words, in order to use string tabs,
<a href="#lrc">LEFT</a>
must be active, or, if
<a href="#quad">QUAD LEFT</a>
or
<a href="#justify">JUSTIFY</a>
are active, the line on which the string tabs are marked must be
broken &#8220;manually&#8221; with
<kbd><a href="#br">.BR</a></kbd>
(but not
<kbd><a href="#spread">.SPREAD</a></kbd>).
</p>

<p class="tip-bottom">
To circumvent this behaviour, I recommend using the
<a href="goodies.html#pad">PAD</a>
to set up string tabs in centered or flush right lines.  Say, for
example, you want to use a string tab to underscore the text of a
centered line with a rule.  Rather than this,
<br/>
<span class="pre-in-pp">
  .CENTER
  \*[ST1]A line of text\*[ST1X]\c
  .EL
  .ST 1
  .TAB 1
  .PT_SIZE 24
  .ALD 3p
  \*[RULE]
  .RLD 3p
  .TQ
</span>
you should do:
<br/>
<span class="pre-in-pp">
  .QUAD CENTER
  .PAD "#\*[ST1]A line of text\*[ST1X]#"
  .EL
  .ST 1
  .TAB 1
  .PT_SIZE 24
  .ALD 3p
  \*[RULE] \" Note that you can&#8217;t use \*[UP ] or \*[DOWN] with \*[RULE]
  .RLD 3p
  .TQ
</span>
</p>
</div>

<!-- -ST- -->

<div class="macro-id-overline">
<h3 id="st" class="macro-id">Set string tabs</h3>
</div>

<div class="box-macro-args">
Macro: <b>ST</b> <kbd class="macro-args">&lt;tab number&gt;  L | R | C | J [ QUAD ]</kbd>
</div>

<p>
After string tabs have been marked off on an input line (see
<a href="#inline-st"><kbd>\*[ST]...\*[STX]</kbd></a>),
you need to &#8220;set&#8221; them by giving them a direction and,
optionally, the <kbd>QUAD</kbd> argument.  In this respect, ST is
like
<a href="#tab-set">TAB_SET</a>
except that you don&#8217;t have to give ST an indent or a
line length (that&#8217;s already taken care of, inline, by
<kbd>\*[ST]...\*[STX]</kbd>).  If you want string tab 1 to be left,
enter
<br/>
<span class="pre-in-pp">
  .ST 1 L
</span>
If you want it to be left and
<a href="definitions.html#filled">filled</a>, enter
<br/>
<span class="pre-in-pp">
  .ST 1 L QUAD
</span>
If you want it to be justified, enter
<br/>
<span class="pre-in-pp">
  .ST 1 J
</span>
See the
<a href="#string-tabs-tut">Quickie tutorial on string tabs</a>
for a full explanation of setting up string tabs.
</p>

<!-- -TAB- -->

<div class="macro-id-overline">
<h3 id="tab" class="macro-id">Call tabs</h3>
</div>

<div class="box-macro-args">
Macro: <b>TAB</b> <kbd class="macro-args">&lt;tab number&gt;</kbd>
</div>
<p class="alias">
<i>Alias:</i> <b>TB</b>
</p>

<p>
After tabs have been defined (either with
<a href="#tab-set">TAB_SET</a>
or
<a href="#st">ST</a>),
TAB moves to whatever tab number you pass it as an argument.  For
example,
<br/>
<span class="pre-in-pp">
  .TAB 3
</span>
<br/>
moves you to tab 3.
</p>

<div id="note-tn" class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> TAB breaks the line preceding it and
advances 1 linespace.  Hence,
<br/>
<span class="pre-in-pp">
  .TAB 1
  A line of text in tab 1.
  .TAB 2
  A line of text in tab 2.
</span>
produces, on output
<br/>
<span class="pre-in-pp">
  A line of text in tab 1.
  A line of text in tab 2.
</span>
If you want the tabs to line up, use
<a href="#tn">TN</a>
(Tab Next), like this:
<br/>
<span class="pre-in-pp">
  .TAB 1
  A line of text in tab 1.
  .TN
  A line of text in tab 2.
</span>
which produces
<br/>
<span class="pre-in-pp">
  A line of text in tab 1.   A line of text in tab 2.
</span>
If the text in your tabs runs to several lines, and you want the
first lines of each tab to align, you must use the
<a href="#multicolumns-intro">multi-column</a> macros.
</p>

<p id="tab-add-note" class="tip-bottom">
<span class="additional-note">Additional note:</span> Any indents
in effect prior to calling a tab are automatically turned off by
TAB.  If you were happily zipping down the page with a left indent
of 2 picas turned on, and you call a tab whose indent from the left
margin is 6 picas, your new distance from the left margin will be 6
picas, not 6 picas plus the 2 pica indent.
</p>
</div>

<!-- -TN- -->

<div class="macro-id-overline">
<h3 id="tn" class="macro-id">Tab Next</h3>
</div>

<div class="box-macro-args">
Macro: <b>TN</b>
</div>
<p class="requires">
In tabs that aren&#8217;t given the <kbd class="normal">QUAD</kbd>
argument when they&#8217;re set up with
<a href="#tab-set" class="normal">TAB_SET</a>
or
<a href="#st" class="normal">ST</a>,
you must terminate the line preceding <kbd class="normal">.TN</kbd>
with the <kbd class="normal">\c</kbd> inline escape.  See the
<a href="#tn-note" class="normal">ADDITIONAL NOTE</a>.
If you find remembering whether to put in the
<kbd class="normal">\c</kbd> bothersome, you may prefer to use the
<a href="definitions.html#inlines" class="normal">inline escape</a>
alternative to
<kbd class="normal">.TN</kbd>,
<kbd class="normal"><a href="inlines.html#TB+">\*[TB+]</a></kbd>,
which works consistently regardless of the fill mode.
</p>

<p>
TN moves over to the next tab in numeric sequence (tab n+1) without
advancing on the page.  See the
<a href="#note-tn">NOTE</a>
in the description of the TAB macro for an example of how TN works.
</p>

<div id="tn-note" class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> You must put text in the
<a href="definitions.html#inputline">input line</a>
immediately after TN. &#8220;Stacking&#8221; of TN&#8217;s is not
allowed.  In other words, you cannot do
<br/>
<span class="pre-in-pp">
  .TAB 1
  Some text
  .TN
  Some more text
  .TN
  .TN
  Yet more text
</span>
The above example, assuming tabs numbered from 1 to 4, should be entered
<br/>
<span class="pre-in-pp">
  .TAB 1
  Some text
  .TN
  Some more text
  .TAB 4
  Yet more text
</span>
<span class="additional-note">Additional note:</span>
In versions of mom prior to 1.1.9, TN did not always work as
advertised on the last
<a href="definitions.html#outputline">output line</a>
of pages that contained a footer trap (e.g. one set with
<a href="#b-margin">B_MARGIN</a>
or in  documents formatted using the
<a href="docprocessing.html#docprocessing">document processing macros</a>).
</p>

<p>
TN has been re-written so that this should no longer be the case.
However, in order for it to work in tabs that have not been given a
<kbd>QUAD</kbd> argument (see
<a href="#tab-set">TAB_SET</a>
and
<a href="#st">ST</a>)
you must always &#8220;join&#8221; <kbd>.TN</kbd> to
the line before it using the
<kbd><a href="#join">\c</a></kbd>
<a href="definitions.html#inlines">inline escape</a>,
as in the following example:
<br/>
<span class="pre-in-pp">
  .TAB_SET 1 0  1P  L
  .TAB_SET 2 1P 20P L
  .TAB 1
  1.\c
  .TN
  The first rule of survival is &#8220;make and keep good friends.&#8221;
</span>
When output, the example will look like this:
<br/>
<span class="pre-in-pp">
  1.  The first rule of survival is &#8220;make and keep good friends.&#8221;
</span>
</p>

<p class="tip-bottom">
Conversely, if you did give a <kbd>QUAD</kbd> argument
to TAB_SET or ST, the
<kbd>\c</kbd> must not be used.
</p>
</div>

<!-- -TQ- -->

<div class="macro-id-overline">
<h3 id="tq" class="macro-id">Tab Quit</h3>
</div>

<div class="box-macro-args">
Macro: <b>TQ</b>
</div>

<p>
TQ takes you out of whatever tab you were in, advances 1 linespace,
and restores the left margin, line length, quad direction and
<a href="definitions.html#filled">fill mode</a>
that were in effect prior to invoking any tabs.
</p>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="multicolumns-intro" class="macro-group">Multiple columns</h2>

<p>
Tabs are not by nature columnar, which is to say that if the text
inside a tab runs to several lines, calling another tab does not
automatically move to the
<a href="definitions.html#baseline">baseline</a>
of the first line in the previous tab.  To demonstrate:
<br/>
<span class="pre-in-pp">
  .TAB 1
  Carrots
  Potatoes
  Broccoli
  .TAB 2
  $1.99/5 lbs
  $0.25/lb
  $0.99/bunch
</span>
produces, on output
<br/>
<span class="pre-in-pp">
  Carrots
  Potatoes
  Broccoli
            $1.99/5 lbs
            $0.25/lb
            $0.99/bunch
</span>
The multi-column macros allow you to set tabs in columnar fashion,
rather than line by line.  When you invoke multi-column mode (with
<kbd><a href="#mco">.MCO</a></kbd> &ndash;
<span style="text-decoration: underline">M</span>ulti-<span style="text-decoration: underline">C</span>olumn <span style="text-decoration: underline">O</span>n),
mom saves the position of the current baseline.
<kbd><a href="#mcr">.MCR</a></kbd>
(<span style="text-decoration: underline">M</span>ulti-<span style="text-decoration: underline">C</span>olumn <span style="text-decoration: underline">R</span>eturn)
at any point while multi-columns are on returns you to the saved
position.  Exiting multi-columns
(<kbd><a href="#mcx">.MCX</a></kbd> &ndash;
<span style="text-decoration: underline">M</span>ulti-<span style="text-decoration: underline">C</span>olumn e<span style="text-decoration: underline">X</span>it)
quits the current tab (if you&#8217;re in one) and moves you to the
bottom of the longest column.  (Note that you do not have to use
multi-columns in conjunction with tabs.)
</p>

<p>
Using our example above, but setting it in multi-column mode,
<br/>
<span class="pre-in-pp">
  .MCO
  .TAB 1
  Carrots
  Potatoes
  Broccoli
  .MCR
  .TAB 2
  $1.99/5 lbs
  $0.25/lb
  $0.99/bunch
  .MCX
</span>
produces
<br/>
<span class="pre-in-pp">
  Carrots   $1.99/5 lbs
  Potatoes  $0.25/lb
  Broccoli  $0.99/bunch
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> Do not confuse MCO with
the
<a href="docprocessing.html#columns">COLUMNS</a>
macro in the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
</p>
</div>

<div id="index-multicolumns" class="macro-list-container">
<h3 class="macro-list">Multi-columns macros</h3>

<ul class="macro-list">
  <li><a href="#mco">MCO</a> &ndash; begin multi-column setting</li>
  <li><a href="#mcr">MCR</a> &ndash; return to top of column</li>
  <li><a href="#mcx">MCX</a> &ndash; exit multi-columns</li>
</ul>
</div>

<!-- -MCO- -->

<div class="macro-id-overline">
<h3 id="mco" class="macro-id">Begin multi-column setting</h3>
</div>

<div class="box-macro-args">
	Macro: <b>MCO</b>
</div>

<p>
MCO (<span style="text-decoration: underline;">M</span>ulti-<span style="text-decoration: underline;">C</span>olumn <span style="text-decoration: underline;">O</span>n) is the macro you use to begin multi-column
setting.  It marks the current
<a href="definitions.html#baseline">baseline</a>
as the top of your columns, for use later with
<a href="#mcr">MCR</a>.
See the
<a href="#multicolumns-intro">introduction to columns</a>
for an explanation of multi-columns and some sample
input.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> Do not confuse MCO with
the
<a href="docprocessing.html#columns">COLUMNS</a>
macro in the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
</p>
</div>

<!-- -MCR- -->

<div class="macro-id-overline">
<h3 id="mcr" class="macro-id">Return to top of column</h3>
</div>

<div class="box-macro-args">
Macro: <b>MCR</b>
</div>

<p>
Once you&#8217;ve turned multi-columns on (with
<kbd><a href="#mco">.MCO</a></kbd>),
<kbd>.MCR</kbd>, at any time, returns you to the top of
your columns.
</p>

<!-- -MCX- -->

<div class="macro-id-overline">
<h3 id="mcx" class="macro-id">Exit multi-columns</h3>
</div>

<div class="box-macro-args">
Macro: <b>MCX</b> <kbd class="macro-args">[ &lt;distance to advance below longest column&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;Optional argument requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
MCX takes you out of any tab you were in (by silently invoking
<kbd><a href="#tq">.TQ</a></kbd>)
and advances to the bottom of the longest column.
</p>

<p>
Without an argument, MCX advances 1 linespace below the longest
column.  Linespace, in this instance, is the
<a href="definitions.html#leading">leading</a>
in effect at the moment MCX is invoked.
</p>

<p>
If you pass the <kbd>&lt;distance&gt;</kbd> argument to MCX, it
advances 1 linespace below the longest column (see above) PLUS the
distance specified by the argument.  The argument requires a unit
of measure; therefore, to advance an extra 6 points below where MCX
would normally place you, you&#8217;d enter
<br/>
<span class="pre-in-pp">
  .MCX 6p
</span>
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> If you wish to advance a precise
distance below the
<a href="definitions.html#baseline">baseline</a>
of the longest column, use MCX with an argument of 0 (zero; no unit
of measure required) in conjunction with the
<a href="#ald">ALD</a>
macro, like this:
<br/>
<span class="pre-in-pp" style="margin-bottom: -12px;">
  .MCX 0
  .ALD 24p
</span>
</p>
</div>

<p>
The above advances to precisely 24 points below the baseline
of the longest column.
</p>

<div class="rule-short" style="margin-bottom: 24px;"><hr/></div>

<!-- ==================================================================== -->

<h2 id="indents-intro" class="macro-group">Indents</h2>

<p>
With mom&#8217;s indents, you can indent from the left, the right,
or both margins.  In addition, mom provides temporary left indents
(i.e. only one line is indented, as at the start of a paragraph)
and &#8220;hanging&#8221; left indents (the reverse of a temporary
indent; the first line isn&#8217;t indented, subsequent lines are).
</p>

<h3 id="indents-handling" class="docs">How mom handles indents</h3>

<p>
Mom provides five kinds of indents: left, right, both, temporary,
and hanging.  Each is invoked by its own name:
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>IL &ndash; Indent Left</li>
<li>IR &ndash; Indent Right</li>
<li>IB &ndash; Indent Both</li>
<li>HI &ndash; Hanging Indent</li>
<li>TI &ndash; Temporary Indent</li>
</ul>

<p>
In addition, there are four macros to control exiting from
indents:
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
<li>IQ &ndash; quit all active indents</li>
<li>ILX &ndash; exit indent style left</li>
<li>IRX &ndash; exit indent style right</li>
<li>IBX &ndash; exit indent style both</li>
</ul>

<p>
This section deals exclusively with IL, IR and IB.  For an
explanation of hanging and temporary indents&mdash;how they work and
how to use them&mdash;see
<a href="#hi">Hanging indents</a>
and
<a href="#ti">Temporary indents</a>.
</p>

<p>
The first time you invoke any of mom&#8217;s indents, you must
supply a measure.  For example,
<br/>
<span class="pre-in-pp">
  .IL 2P
</span>
indents text 2 picas from the left margin (or current tab indent).
</p>

<p>
When you want to exit the above indent, use either
<br/>
<span class="pre-in-pp" style="margin-bottom: -1em;">
  .IQ
</span>
or
<span class="pre-in-pp" style="margin-top: -.5em;">
  .ILX
</span>
The next time you want the same indent, invoke it without the
argument, like this:
<br/>
<span class="pre-in-pp">
  .IL
</span>
As you can see, once you&#8217;ve supplied a measure to an indent
macro mom stores the value, obviating the need to repeat it on
subsequent invocations.  And mom doesn&#8217;t just store the
measure&mdash;she hangs on to it tenaciously.  Arguments passed to
IL, IR and IB are additive.  Consider the following:
<br/>
<span class="pre-in-pp">
  .LL 20P
  .IR 2P    \"Indent right by 2 picas
  A first block of text...
  ...
  ...
  .IQ       \"Turn indent off
  A second block of text...
  ...
  ...
  .IR 2P    \"Indent right by an additional 2 picas (i.e. 4 picas)
  A third block of text...
  ...
  ...
</span>
The first block of text is right indented by 2 picas (i.e. the line
length is shortened by 2 picas to 18 picas).  The second block of
text, after IQ, is, as you&#8217;d expect, set to the full measure.
The third block of text&mdash;the one to pay attention to&mdash;is
not right indented by 2 picas, but rather by 4 picas.  Mom adds
the value of arguments to IL, IR and IB to whatever value is already
in effect.
</p>

<p>
If you wanted the third block of text in the example above to be
right indented by just 2 picas (the original measure given to IR),
you would enter <kbd>.IR</kbd> without an argument.
</p>

<p>
Because indent arguments are additive, putting a minus sign in front
of the argument can be used to subtract from the current value.
In the following example, the first line is indented 18 points,
the second is indented 36 points (18 + 18), and the third is again
indented 18 points (36 - 18).
<br/>
<span class="pre-in-pp">
  .IL 18p     \"Indent left by 18 points      = 18 points
  Now is the time
  .IL 18p     \"Indent left by 18 points more = 36 points
  for all good men to come
  .IL -18p    \"Indent left by 18 points less = 18 points
  to the aid of the party.
</span>
Sometimes, you may want to clear out the stored indent
values&mdash;let mom start indenting with a clean slate, as it
were.  Giving the optional argument <kbd>CLEAR</kbd> to any of the
&#8220;indent quit&#8221; macros resets them to zero.
</p>
<ul style="margin-top: -.5em; margin-bottom: -.5em;">
  <li>IQ CLEAR &ndash; quit and clear all indents</li>
  <li>ILX CLEAR &ndash; quit and clear indent style left</li>
  <li>IRX CLEAR &ndash; quit and clear indent style right</li>
  <li>IBX CLEAR &ndash; quit and clear indent style both</li>
</ul>

<p>
Indent styles may be combined and manipulated separately.  You
could, for example, have a left indent of 4 picas and a right indent
of 6 picas and control each separately, as in the following example.
<br/>
<span class="pre-in-pp">
  .IL 4P     \"Indent left 4 picas
  .IR 6P     \"Indent right 6 picas
  Some text
  .IRX       \"Turn off the right indent only
  More text  \"Text is still indented 4 picas left
</span>
If, at <kbd>.IRX</kbd>, you wanted the text afterwards to have no
indents (either left or right), you would enter <kbd>.IQ</kbd>,
which exits all indent styles at once.
</p>

<p>
A word of advice: Indents are best used only when you have a
compelling reason not to change the current left margin or line
length.  In many instances where indents might seem expedient,
it&#8217;s better to use tabs, or actually change the left margin
or the line length. Mom&#8217;s indenting macros are flexible and
powerful, but easy to get tangled up in.  Personally, I don&#8217;t
use them much, except for cutarounds and multi-level lists à la
html, at which they excel.
</p>

<div class="box-tip">
<p class="tip">
<span class="note">Note:</span> see the section
<a href="docprocessing.html#behaviour">Typesetting macros during document processing</a>
for information and advice on using indents with the
<a href="docprocessing.html#docprocessing">document processing macros</a>.
</p>
</div>

<div id="index-indents" class="macro-list-container">
<h3 class="macro-list">Indents macros</h3>

<ul class="macro-list">
  <li><a href="#il">IL</a> &ndash; Indent left</li>
  <li><a href="#ir">IR</a> &ndash; Indent right</li>
  <li><a href="#ib">IB</a> &ndash; Indent both</li>
  <li><a href="#ti">TI</a> &ndash; Temporary indent, left</li>
  <li><a href="#hi">HI</a> &ndash; Hanging Indent
  <ul style="margin-left: -.5em; list-style-type: disc;">
    <li><a href="#num-lists">Recipe: a numbered list using hanging indents</a></li>
  </ul></li>
  <li><a href="#iq">IQ</a> &ndash; Quit indents, all</li>
  <li><a href="#iq">ILX</a> &ndash; Exit indent style left</li>
  <li><a href="#iq">IRX</a> &ndash; Exit indent style right</li>
  <li><a href="#iq">IBX</a> &ndash; Exit indent style both</li>
</ul>
</div>

<!-- -IL- -->

<div class="macro-id-overline">
<h3 id="il" class="macro-id">Indent left</h3>
</div>

<div class="box-macro-args">
Macro: <b>IL</b> <kbd class="macro-args">[ &lt;measure&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;The optional argument requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
IL indents text from the left margin of the page, or if you&#8217;re
in a tab, from the left edge of the tab.  Once IL is on, the left
indent is applied uniformly to every subsequent line of text, even
if you change the line length.
</p>

<p>
The first time you invoke <kbd>.IL</kbd>, you must give it a
measure.  Subsequent invocations with a measure add to the previous
measure.  A minus sign may be prepended to the argument to subtract
from the current measure.  The
<kbd><a href="inlines.html#inline-stringwidth-groff">\w</a></kbd>
<a href="definitions.html#inlines">inline escape</a>
may be used to specify a text-dependent measure, in which case no
unit of measure is required.  For example,
<br/>
<span class="pre-in-pp">
  .IL \w'margarine'
</span>
indents text by the width of the word &#8220;margarine&#8221;.
</p>

<p>
With no argument, IL indents by its last active value.  See the
<a href="#indents-explanation">brief explanation of how mom handles indents</a>
for more details.
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> Calling a tab (with
<kbd><a href="#tab">.TAB &lt;n&gt;</a></kbd>)
automatically cancels any active indents.
</p>

<p class="tip-bottom">
<span class="additional-note">Additional note:</span> Invoking IL
automatically turns off IB.
</p>
</div>

<!-- -IR- -->

<div class="macro-id-overline">
<h3 id="ir" class="macro-id">Indent right</h3>
</div>

<div class="box-macro-args">
Macro: <b>IR</b> <kbd class="macro-args">[ &lt;measure&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;The optional argument requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
IR indents text from the right margin of the page, or if
you&#8217;re in a tab, from the end of the tab.
</p>

<p>
The first time you invoke <kbd>.IR</kbd>, you must give it a
measure.  Subsequent invocations with a measure add to the previous
indent measure.  A minus sign may be prepended to the argument to
subtract from the current indent measure.  The
<kbd><a href="inlines.html#inline-stringwidth-groff">\w</a></kbd>
<a href="definitions.html#inlines">inline escape</a>
may be used to specify a text-dependent measure, in which case no
unit of measure is required.  For example, <br/>
<span class="pre-in-pp">
  .IR \w'jello'
</span>
indents text by the width of the word &#8220;jello&#8221;.
</p>

<p>
With no argument, IR indents by its last active value.  See the
<a href="#indents-explanation">brief explanation of how mom handles indents</a>
for more details.
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> Calling a tab (with
<kbd><a href="#tab">.TAB &lt;n&gt;</a></kbd>)
automatically cancels any active indents.
</p>

<p class="tip-bottom">
<span class="additional-note">Additional note:</span> Invoking IR
automatically turns off IB.
</p>
</div>

<!-- -IB- -->

<div class="macro-id-overline">
<h3 id="ib" class="macro-id">Indent both</h3>
</div>

<div class="box-macro-args">
Macro: <b>IB</b> <kbd class="macro-args">[ &lt;left measure&gt; &lt;right measure&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;The optional arguments require a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
IB allows you to set or invoke a left and a right indent at the same
time.
</p>

<p>
At its first invocation, you must supply a measure for both indents;
at subsequent invocations when you wish to supply a measure, both
must be given again.  As with IL and IR, the measures are added to
the values previously passed to the macro.  Hence, if you wish to
change just one of the values, you must give an argument of zero to
the other.
</p>

<p>
A word of advice: If you need to manipulate left and right
indents separately, use a combination of IL and IR instead of IB.
You&#8217;ll save yourself a lot of grief.
</p>

<p>
A minus sign may be prepended to the arguments to subtract from
their current values.  The
<a href="inlines.html#inline-stringwidth-groff"><kbd>\w</kbd></a>
<a href="definitions.html#inlines">inline escape</a>
may be used to specify text-dependent measures, in which case no
unit of measure is required.  For example,
<br/>
<span class="pre-in-pp">
  .IB \w&#8217;margarine&#8217; \w'jello'
</span>
left indents text by the width of the word &#8220;margarine&#8221;
and right indents by the width of &#8220;jello&#8221;.
</p>

<p>
Like IL and IR, IB with no argument indents by its last active
values.  See the
<a href="#indents-explanation">brief explanation of how mom handles indents</a>
for more details.
</p>

<div class="box-tip">
<p class="tip-top">
<span class="note">Note:</span> Calling a tab (with
<kbd><a href="#tab">.TAB &lt;n&gt;</a></kbd>)
automatically cancels any active indents.
</p>

<p class="tip-bottom">
<span class="additional-note">Additional note:</span> Invoking IB
automatically turns off IL and IR.
</p>
</div>

<!-- -TI- -->

<div class="macro-id-overline">
<h3 id="ti" class="macro-id">Temporary (left) indent</h3>
</div>

<div class="box-macro-args">
Macro: <b>TI</b> <kbd class="macro-args">[ &lt;measure&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;The optional argument requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
A temporary indent is one that applies only to the first line of
text that comes after it.  Its chief use is indenting the first line
of paragraphs.  (Mom&#8217;s
<a href="docelement.html#pp">PP</a>
macro, for example, uses a temporary indent.)
</p>

<p>
The first time you invoke <kbd>.TI</kbd>, you must give
it a measure.  If you want to indent the first line of a paragraph
by, say, 2
<a href="definitions.html#em">ems</a>,
do
<br/>
<span class="pre-in-pp">
  .TI 2m
</span>
Subsequent invocations of TI do not require you to supply a measure;
mom keeps track of the last measure you gave it.
</p>

<p>
Because temporary indents are temporary, there&#8217;s no need to
turn them off.
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> Unlike IL, IR and IB,
measures given to TI are NOT additive.  In the following example,
the second <kbd>.TI&nbsp;2P</kbd> is exactly 2 picas.
<br/>
<span class="pre-in-pp" style="margin-bottom: -18px;">
  .TI 1P
  The beginning of a paragraph...
  .TI 2P
  The beginning of another paragraph...
</span>
</p>
</div>

<!-- -HI- -->

<div class="macro-id-overline">
<h3 id="hi" class="macro-id">Hanging indent</h3>
</div>

<div class="box-macro-args">
Macro: <b>HI</b> <kbd class="macro-args">[ &lt;measure&gt; ]</kbd>
</div>
<p class="requires">
&bull;&nbsp;The optional argument requires a <a href="definitions.html#unitofmeasure">unit of measure</a>
</p>

<p>
A hanging indent looks like this:
<br/>
<span class="pre-in-pp">
  The thousand injuries of Fortunato I had borne as best I
    could, but when he ventured upon insult, I vowed
    revenge.  You who so well know the nature of my soul
    will not suppose, however, that I gave utterance to a
    threat, at length I would be avenged...
</span>
The first line of text &#8220;hangs&#8221; outside the left margin.
</p>

<p>
In order to use hanging indents, you must first have a left indent
active (set with either
<kbd><a href="#il">.IL</a></kbd>
or
<kbd><a href="#ib">.IB</a></kbd>).
Mom will not hang text outside the left margin set with
<kbd><a href="#l-margin">.L_MARGIN</a></kbd>
or outside the left margin of a tab.
</p>

<p>
The first time you invoke <kbd>.HI</kbd>, you must give
it a measure.  If you want the first line of a paragraph to hang by,
say, 1 pica, do
<br/>
<span class="pre-in-pp">
  .IL 1P
  .HI 1P
</span>
Subsequent invocations of HI do not require you to supply a measure;
mom keeps track of the last measure you gave it.
</p>

<p>
Generally speaking, you should invoke HI immediately prior to the
line you want hung (i.e. without any intervening
<a href="definitions.html#controllines">control lines</a>).
And because hanging indents affect only one line, there&#8217;s no
need to turn them off.
</p>

<h4 id="num-lists" class="macro-id">Recipe: Numbered lists using hanging indents</h4>

<div class="box-tip" style="margin-top: -.5em; margin-bottom: -.5em;">
<p class="tip">
<span class="note">Note:</span> mom has macros for setting lists (see
<a href="docelement.html#list-intro">Nested lists</a>).
This recipe exists to demonstrate the use of hanging indents only.
</p>
</div>

<p style="margin-top: 1.5em;">
Consider the following example:
<br/>
<span class="pre-in-pp">
  .PAGE 8.5i 11i 1i 1i 1i 1i
  .FAMILY  T
  .FT      R
  .PT_SIZE 12
  .LS      14
  .JUSTIFY
  .KERN
  .SS 0
  .IL \w'\0\0.'  \"Indent left by 2 figure spaces and a period
  .HI \w'\0\0.'  \"Hang first line back by 2 figure spaces and a period
  1.\0The most important point to be considered is whether the
  answer to the meaning of Life, the Universe, and Everything
  really is 42.  We have no-one&#8217;s word on the subject except
  Mr. Adams&#8217;.
  .HI
  2.\0If the answer to the meaning of Life, the Universe,
  and Everything is indeed 42, what impact does this have on
  the politics of representation?  42 is, after all not a
  prime number.  Are we to infer that prime numbers don&#8217;t
  deserve equal rights and equal access in the universe?
  .HI
  3.\0If 42 is deemed non-exclusionary, how do we present it
  as the answer and, at the same time, forestall debate on its
  exclusionary implications?
</span>
First, we invoke a left indent with a measure equal to the width of
2
<a href="definitions.html#figurespace">figures spaces</a>
plus a period (using the
<a href="inlines.html#inline-stringwidth-groff"><kbd>\w</kbd></a>
inline escape).  At this point, the left indent is active; text
afterwards would normally be indented.  However, we invoke a
hanging indent of exactly the same width, which hangs the first
line (and first line only!) to the left of the indent by the
same distance (in this case, that means &#8220;out to the left
margin&#8221;).  Because we begin the first line with a number,
a period, and a figure space, the actual text (&#8220;The most
important point...&#8221;) starts at exactly the same spot as the
indented lines that follow.
</p>

<p>
Notice that subsequent invocations of <kbd>.HI</kbd> without a
measure produce exactly the same effect.
</p>

<p>
Paste the example above into a file and preview it with <kbd>groff
-mom -X &lt;filename&gt;</kbd> to see hanging indents in action.
</p>

<div class="box-important">
<p class="tip">
<span class="important">IMPORTANT:</span> Unlike IL, IR and IB,
measures given to HI are NOT additive.  Each time you pass a measure
to HI, the measure is treated literally.
</p>
</div>

<!-- -IX- -->

<div class="macro-id-overline">
<h3 id="iq" class="macro-id">Quitting indents</h3>
</div>

<div class="box-macro-args">
Macro: <b>IQ</b> <kbd class="macro-args">[ CLEAR ]</kbd> (quit any/all indents &mdash; see IMPORTANT NOTE)
</div>
<br/>

Macro: <b>ILX</b> <kbd class="macro-args">[ CLEAR ]</kbd> (exit Indent Left)
<br/>

Macro: <b>IRX</b> <kbd class="macro-args">[ CLEAR ]</kbd> (exit Indent Right)
<br/>

Macro: <b>IBX</b> <kbd class="macro-args">[ CLEAR ]</kbd> (exit Indent Both)

<div class="box-important">
<p class="tip-top">
<span class="important">IMPORTANT NOTE:</span> Formerly, the macro
for quitting all indents was IX.  This usage is now deprecated, in
favour of IQ.  IX will continue to behave as before, but mom will
issue a warning to stderr indicating that you should update your
documents.
</p>

<p class="tip-bottom">
As a consequence of this change, ILX, IRX and IBX may now also be
invoked as ILQ, IRQ and IBQ.  Both forms are acceptable.
</p>
</div>

<p>
Without an argument, the macros to quit indents merely restore your
original margins and line length.  The measures stored in the indent
macros themselves are saved so you can call them again without
having to supply a measure.
</p>

<p>
If you pass these macros the optional argument <kbd>CLEAR</kbd>,
they not only restore your original left margin and line length, but
also clear any values associated with a particular indent style.
The next time you need an indent of the same style, you have to
supply a measure again.
</p>

<p>
<kbd>.IQ&nbsp;CLEAR</kbd>, as you&#8217;d suspect,
quits and clears the values for all indent styles at once.
</p>

<div class="rule-long"><hr/></div>

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