Specifies whether to generate the list of elements this element may substitute for (that is, the given element may be used anywhere instead of the elements in the list).
<p>
This list will appear under the heading <i>"Substitutes for elements"</i>.
<p>
<b>Applies To:</b>
<dl><dd>
Global Elements
</dd></dl>
<p>
<b>See Also Parameter:</b>
<dl><dd>
<i>"Details | Component Documentation | Component Profile | Subst.Gr | List of group heads"</i> 
</dd></dl>