type, e.g.
which image formats can be used, levels of scripting, style sheet
support, and so on.</p>

<p>For product designers this enables various groups to define
their own standard profile.</p>

<p>For authors this will obviate the need to write several
different versions of documents for different clients.</p>

<p>For special groups such as chemists, medical doctors, or
mathematicians this allows a special profile to be built using
standard HTML elements plus a group of elements geared to the
specialist