source: stylesheets/lfs-xsl/docbook-xsl-1.78.1/xhtml5/README@ 111bb20

DocBook stylesheets for HTML5 output 
=============================================

This directory contains XSL stylesheets
for generating HTML5 output from DocBook content.
For information on HTML5, see:

http://dev.w3.org/html5/spec/Overview.html

Note that there is no schema available for HTML5, by design.

The output of these stylesheets is the XML serialization of
HTML5.  There is no provision for generating the HTML
serialization of HTML5 with these stylesheets.

These HTML5 stylesheets are also used by the EPUB3
stylesheets included in this distribution.

These stylesheets are customizations of the
existing stylesheets in the "xhtml/" directory.
Using a customization layer enables the HTML5
stylesheets to inherit all the features of the
XHTML stylesheets while making the minimum changes
for them to produce valid HTML5.

If you are processing DocBook 5 document, you should use
the namespaced version of the stylesheets, with "-ns-"
in the directory name.


Usage
-----------
You should be able to apply any of these stylesheet files
to a DocBook document as with any other DocBook stylesheet:

xhtml5/docbook.xsl         - Single file output.
xhtml5/chunk.xsl           - Chunked output.
xhtml5/profile-docbook.xsl - Profiled single file output.
xhtml5/profile-chunk.xsl   - Profiled chunk output.
xhtml5/chunkfast.xsl       - Chunked output with precomputed chunks.

Do not attempt to directly use the following two stylesheet files:

xhtml-docbook.xsl
xhtml-profile-docbook.xsl

Those are copies of the corresponding files in the
xhtml/ directory, modified to remove the doctype
declarations in the xsl:output elements.  They were also
modified to import from the original xhtml/ directory.
They will produce xhtml output, not HTML5 output.
They are imported by the xhtml5 stylesheet files.

Testing
--------------

The HTML5 output of these stylesheets should pass the
W3C online validator, available here:

http://validator.w3.org/