Publican is a single source publishing tool based on DocBook XML.

Important notes:

While building the package an active network connection is required for
both 4.5 and 5.0 document validation to work correctly.

This package provides a fixed docbook catalog located at
/usr/share/publican/catalog. Publican is patched to always use this
catalog. There are some problems with docbook validation with the
original slackware dockbook catalog and Publican's dependencies that
result in validation problems and failures for docbook 4.5 documents.

For more details see
https://www.linuxquestions.org/questions/slackware-14/linuxdoc-tools-problem-when-validating-docbook-4-5-documents-4175623483/

The resulting package picks the appropriate slackware's docbook 4.5
xml's using the provided fixed catalog for docbook 4.5 documents. For
documents that are written in docbook 5.0 an active network connection
is required since docbook 5.0 is not included in slackware-14.2.

fop is an alternative dependency to wkhtmltox for producing pdf
documents. fop use is deprecated upstream and Publican is not
compatible with fop version 2.0, an older fop version is required.
The recommended dependency for correct pdf's is wkhtmltox.

For more information on how to use publican, see the user's guide in
/usr/doc/Publican-4.3.2/Users_Guide