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According to the format of the output file, the macro package defines a given 
symbol: 

<dl>

<li > <code>latex</code> when the output format is LaTeX,

<li > <code>html</code> when the output format is HTML,

<li > <code>man</code> when the output format is groff in conjunction with the
    man macro package,

<li > <code>ms</code> when the output format is groff with the ms package,

<li > <code>sgml</code> when the output format is SGML,

<li > <code>txt</code> when the output format is plain ASCII.

</dl>

The defined symbol can be tested in a document to determine the conversion 
type.  

Furthermore, the package defines the following macros to send litteral text 
(commands in the output format) to the output file:

<dl>

<li > <code>latexcommand(cmd)</code>: sends the LaTeX command <code>cmd</code> when in LaTeX 
    conversion mode. The <code>cmd</code> is not further expanded.

<li > <code>htmlcommand(cmd)</code>: sends the HTML command <code>cmd</code> when in HTML 
    conversion mode.  The <code>cmd</code> is not further expanded.

<li > <code>htmltag(tag)(onoff)</code>: sends <code>&lt;tag&gt;</code> to the output when <code>onoff</code>
    is nonzero, or sends <code>&lt;/tag&gt;</code> when <code>onoff</code> is zero. Only active in
    HTML conversions.

<li > <code>mancommand(cmd)</code>: sends <code>cmd</code> to the output when in man 
    conversion mode.  The <code>cmd</code> is not further expanded.

<li > <code>mscommand(cmd)</code>: sends <code>cmd</code> to the output when in ms
    conversion mode. The <code>cmd</code> is not further expanded.

<li > <code>roffcmd(dotcmd)(trailer)(secondline)(thirdline)</code>: sends a command 
    to the output when in <code>man</code> or <code>ms</code> conversion mode. The <code>dotcmd</code> is 
    the typical <code>groff</code> command that starts with a dot. All other arguments 
    may be empty, but when given are interpreted as follows. The <code>trailer</code> 
    follows the <code>dotcmd</code> on the same line. The <code>secondline</code> is sent on a 
    separate line following the <code>dotcmd</code> and <code>trailer</code>. The <code>thirdline</code> 
    is sent after that. Of the four arguments, <code>dotcmd</code> and <code>thirdline</code>
    are <strong>not</strong> subject to further expansion. All other arguments are further 
    expanded if necessary.     

The <code>roffcmd</code> macro illustrates the complexity of dot-commands for the 
    divers <code>groff</code> macro packages. E.g., a section title for the <code>man</code> 
    package should look as

<pre>
.SH "Section Title"
</pre>

<p>while the same command for the <code>ms</code> macro package must be sent as
<p><pre>
.SH
Section Title
.PP
</pre>

<p>The <code>roffcmd</code> macro can be used to send these commands to the output 
    file as follows:
<p><pre>
COMMENT(For the man output format:)
roffcmd(.SH)("Section Title")()()

COMMENT(For the ms output format:)
roffcmd(.SH)()(Section Title)(.PP)()
</pre>

<p><li > <code>sgmlcommand(cmd)</code>: sends the SGML command <code>cmd</code> when in SGML 
    conversion mode. The <code>cmd</code> is not further expanded.
<p><li > <code>sgmltag(tag)(onoff)</code>: sends <code>&lt;tag&gt;</code> when <code>onoff</code> is nonzero,
    or sends <code>&lt;/tag&gt;</code> when <code>onoff</code> is zero. Only active in SGML 
    conversions.
<p><li > <code>txtcommand(cmd)</code>: implemented for compatibility reasons, though 
    a `command' in plain ASCII output doesn't make much sense. The usefulness
    of this macro is rather in the fact that it only produces output when in
    ASCII conversion mode.
<p></dl>
<p>The above commands can be used to quickly implement a macro. E.g., the macro 
package implements the <code>it</code> macro (which starts an item in a list) as:
<p><pre>
DEFINEMACRO(it)(0)(\ 
        latexcommand(\item )\ 
        htmlcommand(&lt;li&gt; )\ 
        ....)
</pre>

<p>Depending on the output format, <code>it()</code>  will lead to one of the above 
expansions.
<p>The above described <em>format</em><code>command()</code> macros are implemented to send not 
further expanded strings (i.e., commands) to the output. The macro package 
also implements <code>when</code><em>format</em><code>()</code> macros to send any text, which is 
then subject to further expansion. These <code>when...()</code> macros are:
<p><dl>
<p><li > <code>whenlatex(text)</code>: sends <code>text</code> when in LaTeX conversion mode,
<p><li > <code>whenhtml(text)</code>: sends <code>text</code> when in HTML conversion mode,
<p><li > <code>whenman(text)</code>: sends <code>text</code> when in man conversion mode,
<p><li > <code>whenms(text)</code>: sends <code>text</code> when in ms conversion mode,
<p><li > <code>whentxt(text)</code>: sends <code>text</code> when in ASCII conversion mode,
<p><li > <code>whensgml(text)</code>: sends <code>text</code> when in SGML conversion mode.
<p></dl>
<p><strong>Note again</strong> that the difference between the <code>when</code><em>format</em><code>()</code> macros 
and the <em>format</em><code>command()</code> macros is, that the former will expand their 
argument while the latter will not. As an example, consider the following code 
fragment: 
<p><pre>
You are now reading
        whenlatex(a LaTeX-generated 
                  footnote(LaTeX is a great 
		           document language!)
                  document)
        whenhtml(a HTML document via your
                 favorite browser)
</pre>

<p>The <code>when</code><em>format</em><code>()</code> macros are used here to make sure that the 
arguments to the macros are further expanded; this makes sure that the 
<code>footnote</code> macro in the <code>whenlatex</code> block gets treated as a footnote.
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