<pre>
    .UNDERSCORE_WEIGHT 1.5
</pre>

prior to invoking <kbd>.UNDERSCORE</kbd>.  Every subsequent
instance of <kbd>.UNDERSCORE</kbd> will use this weight.
</p>

<p>
<strong>Mom</strong>'s default underscore weight is 1/2 point.
</p>

<a name="NOTES_UNDERSCORE"></a>

<h4><u>NOTES:</u></h4>

<p>
<strong>UNDERSCORE</strong> does not work across line breaks in
output copy, which is to say that you can't underscore a multi-line
passage simply by putting the text of the whole thing in the string
you pass to <s