Specify whether to show the information about the substitution groups, in which this element is involved
(i.e. affiliated, head or member of). This may include:
<ul>
  <li>The list (or number) of elements which this element may substitute for.</li>
  <li>The list (or number) of elements that may substitute for this element.</li>
</ul>
<b>Applies To:</b>
<dl><dd>
Global Elements
</dd></dl>

<b>Nested Parameter Group:</b>
<dl><dd>
Controls what exactly is included in the substitution group info.
</dd></dl>