The gnome-doc-utils package is a collection of documentation utilities
for the GNOMEproject. Notably, it contains utilities for building
documentation and all auxiliary files in your source tree. It also
contains the DocBook XSLT stylesheets that were once distributed with
Yelp. Starting with GNOME 2.8, Yelp requires gnome-doc-utils for XSLT.
It also contains the Python program xml2po that extracts translatable
content from XML documents and outputs gettext-compatible POT files.
For simple tags, it works out-of-the-box. For complicated tags, provide
a list of all tags that are considered "final" (tags with contents that
should be put into one "message" in the POT file), "ignored" (skipped
over), and "space preserving".

Sane defaults are available for DocBook documents and other common
document types (like GNOME Summaries and XHTML). For other kinds of
documents, it is possible to use -a (--automatic-tags) to choose
suitable translatable pieces.