Works through adding additional attributes to elements.
Example:
<sect1 id="installation"> <title>Installation</title> <para>You must first have full access to the system.</para> <para os="windows">On Windows 95/98/NT, run <filename>INSTALL.EXE</filename> and follow the instructions. </para> <para os="linux">In Linux, install <filename>foo-1.0-1.i386.rpm</filename>.</para> </sect1>
Special stylesheets will now make a first pass through to extract relevant elements, then do further processing.
Attributes can be added to individual paragraphs or to entire sections