To write SGML or HTML?

[mikebw at bilow.bilow.uu.ids.net (Mike Bilow)]

Christoph Doerbeck A242369 wrote in a message to Mike Bilow:

 CDA> Question?  When it comes to writing documentation these
 CDA> days, what arguments could be made for the various mark up
 CDA> languages?

 CDA> I'm starting to whip out my presentation for the Video4Linux
 CDA> demo in December, and I'd like to know whether or not it's
 CDA> worth learning yet another mark-up (SGML) ? 

 CDA> Comments?

SGML is not a markup language.  It is more correctly understood as a
meta-markup language.

SGML provides a framework for defining a markup language.  A particular markup
language is instantiated within SGML through the creation of a "Document Type
Definition (DTD)."  The most commonly encountered example of a markup language
instantiated by an SGML DTD is HTML.

Technically, a DTD is a table of tags and syntax information which is expressed
in a standard format.  It is therefore possible to write a generalized SGML
toolkit which can read DTDs and do validity checking or other processing on
documents written using one of those DTDs.

To do anything which involves semantics, the utilities must be bound to a
specific markup language and DTD.  For example, one could not expect to write a
web browser for any SGML language, but only for one or more particular DTDs. In
fact, each HTML version consists of at least one distinct DTD, and a single
HTML version may consist of more than one DTD if the drafts were public.

The Linux Documentation Project has defined a specific SGML DTD for its own
use, and authors contributing to the LDP are expected to use it.  This is
required for HOWTO and other long documents, but is optional for mini-HOWTO
documents.  The main advantage to having the primary version of LDP documents
be in this SGML DTD form is that translators have been written to export these
documents into ASCII text, HTML, DVI, TEX, and a number of other handy forms.

The learning curve for the LDP DTD is trivial.
 
-- Mike


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