<p tal:omit-tag="">Content</p>
<p tal:omit-tag=""></p>
<img tal:omit-tag="">

<p tal:omit-tag="string:Yes">Content</p>
<p tal:omit-tag="string:Yes"></p>
<img tal:omit-tag="string:Yes">

<p tal:omit-tag="nothing">Content</p>
<p tal:omit-tag="nothing"></p>
<img tal:omit-tag="nothing">

<p tal:define="txt string:Yes" tal:omit-tag="" tal:content="txt">No</p>
<p tal:define="txt string:Yes" tal:omit-tag="" tal:replace="txt">No</p>
<p tal:omit-tag="" tal:content="default">Yes</p>
<p tal:omit-tag="" tal:replace="default">Yes</p>