This directory contains a number of auxiliary files that are used by the
 docbook build system to convert the documentation in docbook-xml format to
 various output formats.
 * catalog.xml:
     This is a XML catalog file. The file is used by the tools that process
     docbook sources to map public identifiers, which are commonly found in
     docbook source files, such as 
       "-//OASIS//DTD DocBook XML V4.3//EN"
     to local files. The default version of the file refers to a generic 
     catalog file that is commonly found in /etc/xml/catalog.
     You can modify the file if you want to use a particular version of docbook
     schema files or XSL stylesheets to produce the output. This is very useful
     because there is no need to modify source docbook files, the catalog file
     can be used to re-map the public identifier in those files to a local (and
     possibly customized) version of the schema or stylesheets.
 * common.xsl:
     This file contains docbook XSL stylesheet customizations that are shared
     by all output-specific XSL files, for example, the code that strips
     leading and trailing whitespace in <screen> sections is located here.
 * dep.xsl:
     This file contains a special XSL stylesheet which can be used to produce a
     file with dependencies for any given docbook source file. The stylesheet
     traverses docbook documents and looks for files included with the
     xi:include mechanism, or for files included by docbook tags, such as
     images, screen listings, etc. The list of dependencies is then written in
     a separate file and the file can be included in a Makefile that is used to
     build documentation. This is all done by the docbook makefile system.
 * html.chunked.xsl: 
     The stylesheet in this file is used to generate HTML output split in
     multiple files. This is useful if you need to generate HTML files with
     documentation for browsers that do not support XHTML.
 * Makefile:
     This is the main Makefile of the Docbook build system. Rules implemented
     in this Makefile can be used to validate docbook documents, generate lists
     of dependendies, generate HTML, plain-text, READMEs, and other output
     formats out of docbook documents. This file is not meant to be used
     directly. Instead, each directory with docbook source files should have
     its own minimal Makefile which includes this file.
 * man.xsl:
     This stylesheet can be used to convert docbook sources into man pages. The
     docbook build system uses this stylesheet to convert docbook files with
     man pages contents to real man pages, some modules contain such docbook
 * readme.xsl:
 	This stylesheet is used to generate module README files from docbook sources.
 * sr-doc.css:
     The CSS stylesheets that are used for online HTML documentation generated
     from docbook sources.
 * txt.xsl:
     The XSL stylesheet used to generate plain text version of the
     documentation.  XHTML stylesheets are used to generate XHTML code that is
     then fed to lynx to produce plain a text version. This stylesheet contains
     XHTML customization that are applied only when a plain-text output is
   -- Jan Janak <>