DOCBOOK: modifiying DTD

[Shang-Lin Chen <schen@its.caltech.edu>]

Right now I'm learning DocBook from the online version of the "Definitive
Guide." When i tried the "MethodName" example in the "Customizing
DocBook" chapter and ran db2html, I received error messages saying that
the "<" character is not allowed in declaration subset, the parameter
entity "smallcptr.char.mix" is not defined, and the parameter entities in
the attributes are also not defined. The messages also complained about
the new "MethodName" identifier and the "chapter," "Title," and other
parameter entities in "local.tech.char.class" being undefined. I copied
the DTD and the SGML file directly from the documentation and followed all
the directions, so I don't think there's anything wrong withmy syntax. Do
I need to do somtething else, like modify the stylesheets?