The DocBook DTD defines structural and content-based SGML markup
for computer documentation, with a primary emphasis on software
documentation and related classes of technical documents. Its
main high-level hierarchical structures are for books, reference
entries (for example, ``man pages''), and articles. It is
maintained by the DocBook Technical Committee of OASIS.

This port contains DocBook 4.5.  Note that DocBook 4.5 includes
the XML DocBook DTD as part of the SGML DTD distribution.  If
you do not need SGML DTD you should install:
  textproc/docbook-xml-450
instead.  There are no conflicts if both ports are installed
but you will have duplicates of most of the files.

WWW: http://www.docbook.org/specs/docbook-4.5-spec-cs-01.html