tion</code> exists but not
whether it makes any sense in the current menu. The user has to take
care that a function name between braces (or any sequence of them)
is appropriate.  Strange behavior can result when it is not.
</p>
<br>
<p>The format of <code>key</code> should be one of:
</p>
<blockquote class="indentedblock">
<dl compact="compact">
<dt><code>^<var>X</var></code></dt>
<dd><p>where <var>X</var> is a Latin letter, or one of several
ASCII characters (@, ], \, ^, _), or the word &quot;Space&quot;.