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From Ross Gardler <>
Subject Re: Documentv20 --> DocBook
Date Mon, 29 Dec 2003 22:37:33 GMT
Peter Hargreaves wrote:
> The following is to strengthen the case for DocBook (or some other media
> independent DTD) as the central document type.

<snip what="points 1-4 saying we need a generic media independant format"/>

> 4) The skin should be the very first time that presentational, layout
> and target media languages (such as XHTML, fo, WML, PDF, DOC,etc) are
> used.


XHTML doesn't contain presentational information. It does guide 
presnetation, but it doesn't dictate it. It is the final rendering into 
the target media language that has the actual presentation information 
(such as XHTML+CSS, note the '+CSS', PDF, DOC etc.)

Just because it is called X*HTML* doesn't mean it has to be rendered in 
a browser.

> 5) Some legacy source content DTDs are derived from target media
> languages but they need not influence the choice of central DTD.

True, but the XHTML Vs Docbook discussion has been had many times in the 
past, my original post was prompted because I have been reading the 
archives alot lately and whenever XHTML Vs Docbook xomes up XHTML seems 
to win out. For good reasons, lets see if it still does...

<snip what="pints 6-7 saying docbok is media independant and 
semantically rich"/>

> 8) A central document type, standing between content and skin, must not
> filter out richness of meaning of document structure, or it will
> undermine the presentational possibilities.

I have recently been conviced that at the forrest intermediate level all 
the semantic information I *thought* I needed is actually presentational 
information (see

As a result it can all be captured in the class attribute. How it is 
presented is then up to the rendering engine, which is exactly what 
should happen. I have to admit, I was suprised to find that I ended up 
agreeing with this view, but agree I did once I tried to justify my case 
with what I thought were rock solid use cases!

> 9) A central document type must therefore be very rich in its
> description of document structure and meaning - without bias toward
> media type.

Quite the reverse. It should be as simple as possible, semantic meaning 
has no place at the presentaional layer, it is only presentation that is 

Can you give us a use case in which we need semantic meaning at the 
intermediate stage in order to do anything *other* than effect how the 
data is presented.

(He He, this is exactly what Jeff asked me to do and I thought I could 
do it, now I'm a convert - ex-smokers are always the worst :-)).

> 10) The central document type might be user chooseable, if Forrest can
> cope with the complexity of this?

Interesting... what would Forrest gain from this? We have user 
selectable source formats, isn't that what is important from the user 

Having said that, you can easily change your local xmaps in order to use 
a different intermediate format for certain documents if you find the need.

> For those not familiar, here is an extract from Norman Walsh's DocBook:
> The Definative Guide:
> "DocBook provides a system for writing structured documents using SGML
> or XML. It is particularly well-suited to books and papers about
> computer hardware and software, though it is by no means limited to
> them. DocBook is a document type definition (DTD). Because it is a large
> and robust DTD, and because its main structures correspond to the
> general notion of what constitutes a book, DocBook has been adopted by a
> large and growing community of authors. DocBook is supported “out of the
> box” by a number of commercial tools, and support for it is rapidly
> growing in a number of free software environments. In short, DocBook is
> an easy-to-understand and widely used DTD. Dozens of organizations use
> DocBook for millions of pages of documentation, in various print and
> online formats, worldwide."

For me this indicates it can be used as a source format, but not as an 
intermediate format. The key phrases for me are:

"particularly well-suited to books and papers about computer hardware 
and software"


"its main structures correspond to the general notion of what 
constitutes a book"

- I use forrest for training materials. Docbook *could* be used as a 
source format but it is not ideal in my domain. I use other formats as 
my source that have been designed for the purpose. By converting to 
docbook as an intermediate format I will be losing semantic information, 
which is something you say I shouldn't do, but something I am now 
comfortable with (see above).

My point is, *no* (usable) intermediate format will be so expressive 
that it can accomodate all users.

On the XHTML side of things, the following text from the XHTML working 
draft convinces me that XHTML should be the intermediate format:

"The XHTML family is designed with general user agent interoperability 
in mind. Through a new user agent and document profiling mechanism, 
servers, proxies, and user agents will be able to perform best effort 
content transformation. Ultimately, it will be possible to develop 
XHTML-conforming content that is usable by any XHTML-conforming user agent."

If I am going to lose some semantic information I want to be sure that 
the language I am using is so generic that I don;t lose any 
presentational information regardless of the media type. That is what 
XHTML is designed for.

Am I making any sense?


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