This document is deliberately not an exhaustive discussion of SGML, the DTDs listed, and the FreeBSD Documentation Project. For more information about these, you are encouraged to see the following web sites. The FreeBSD Documentation Project web pages The FreeBSD Handbook The SGML/XML web page, a comprehensive SGML resource Gentle introduction to SGML The World Wide Web Consortium The HTML 4.0 specification The DocBook Technical Committee, maintainers of the DocBook DTD DocBook: The Definitive Guide, the online documentation for the DocBook DTD. The DocBook Open Repository contains DSSSL stylesheets and other resources for people using DocBook. The Linux Documentation Project web pages