 general are:</p>

<ul>
<li>Document developers and user agent designers are constantly
discovering new ways to express their ideas through new markup. In XML, it is
relatively easy to introduce new elements or additional element
attributes.  The XHTML family is designed to accommodate these extensions
through XHTML modules and techniques for developing new XHTML-conforming
modules (described in the forthcoming XHTML Modularization specification).
These modules will permit the combination of existing and
ne