additional
semantics may be defined in the prose description of the
element.</dd>

<dt><a name="facilities" id="facilities">Facilities</a></dt>

<dd>Functionality includes <span class="term">elements</span>,
<span class="term">attributes</span>, and the semantics
associated with those <span class="term">elements</span> and
<span class="term">attributes</span>. An implementation
supporting that functionality is said to provide the necessary
facilities.</dd>

<dt>Implementation</dt>

<dd>An implementation is 