The OPTGROUP element allows authors to group selection list choices into a hierarchy. This
is particularly helpful to non-visual user agents when large numbers of options are
available to choose from. Possible rendering of this element could be a collapsible hierarchy
list of OPTION element content or some presentatin conveying the hierarchy relationship of
the OPTION contents. Browsers not supporting this element will "see" only a traditional flat
list of OPTION elements. The LABEL attribute for this element is used to provide shorter
labels for the nodes of the hierarchical menus.
Attributes:
disabled - This is a stand-alone
attribute which indicates the element is initially non-functional.
label - This specifies a shorter
alternate label for use in identifying the sub-group of options.
Example code:
<select NAME="Familytree">
<option LABEL="Bill" VALUE="bill">Bill Smith
<option LABEL="Mary" VALUE="mary">Mary Smith
<optgroup LABEL="Joe">
<option VALUE="michael">Michael Smith
<option VALUE="susan">Susan Smith
<option VALUE="howard">Howard Smith
</optgroup>
</select>
