Re: [docbook] DocBook/XML catalog question

[Michael Smith <smith@xml-doc.org>]

Jeroen Ruigrok/asmodai <asmodai@in-nomine.org> writes:

> a quick question since I help maintain DocBook/XML for pkgsrc.org.
> 
> DocBook/XML 4.1.2 - 4.4 are all backwards compatible, does this mean that I
> can just add this to catalog.xml:
> 
> <public publicId="-//OASIS//DTD DocBook XML V4.3//EN"
>   uri="docbookx.dtd"/>
> 	   
> <public publicId="-//OASIS//DTD DocBook XML V4.2//EN"
>   uri="docbookx.dtd"/>
> 	   
> <public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN"
>   uri="docbookx.dtd"/>
> 
> This is what some people are suggesting.  I am a bit hesitant to do this,
> due to the fact that if you explicitely want to validate against 4.1.2 or
> 4.2 you will have a bit wider specification if you use 4.4's DTD.

I think you are right to be hesitant.

The need to validate against constraints of an earlier version of
the DTD is a valid need. That is the exact use-case for keeping
the older DTDs around. Although the DocBook Project XSL
stylesheets support everything -- or most of everything -- in
DocBook 4.4 (and DocBook 4.5 and even much of DocBook NG/5), the
DocBook DSSSL stylsheets do not. People using DocBook DSSSL should
probably stick to validating against DocBook 4.2. Or maybe even
DocBook 4.1.2. Otherwise, they could end up adding markup to their
docs, and not getting expected output from the DSSSL toolchain.

And there are tools for processing DocBook other than the DocBook
Project XSL and DSSSL stylesheets. For some examples, see here:

  http://wiki.docbook.org/topic/DocBookPublishingTools

The DocBook2X tools, for example, do not support features that are
new in DocBook 4.3 and DocBook 4.4.

> Or wouldn't it matter that much?

I think it matters to users. I realize that package and distro
maintainers may think it is a big PITA to keep the old stuff
around. But that is what everybody should be doing unless you want
users to end up creating docs that they can't process correctly
with whatever their chosen tool set may be.

  --Mike

-- 
Michael Smith
http://sideshowbarker.net/

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