Re: DOCBOOK: details of DocBook versioning policy

[Norman Walsh <ndw@nwalsh.com>]

/ "Matt G." <matt_g_@hotmail.com> was heard to say:
| Isn't there a possibility that a patch release will alter the DTD in
| an incompatible fashion, such that a valid XML DocBook x.y.z document
| might not be valid for x.y.(z+n) (for n > 0)?  Or is this explicitly
| prevented, requiring that the issue be addressed in the next major
| revision? 

The latter. The TC does not make backwards incompatible changes in
point releases. It's even "worse" than that. If the TC decided tomorrow
to make a backwards incompatible change, it would have to be announced
in DocBook V5 and could not be implemented until DocBook V6.

| If the latter, then it would seem convenient to treat minor
| revisions as RCS branch revisions, such that it aliases to the latest

There is no direct correlation between the revision numbers (or branch
numbers) in CVS and the actual DTD releases. I do, as a matter of course,
provide tags for the revisions that form a particular release, but the
CVS repository is not the official source for DocBook. The official
sources for DocBook are the files that exist on www.oasis-open.org.

| If the above versioning policy is followed, then documents should only
| reference a specific minor revision, while the application is free to
| use the latest compatible patch/superset.  This could be done through
| catalog files.

You can arrange for this behavior using catalogs without changing the
versioning policy. Just make your catalog point to the most recent
point release for all public identifiers and URIs that are appropriate.

(If we were starting over, I would very likely argue that we should
implement a versioning policy along the lines you suggest, but it
doesn't seem worth the fuss of changing now)

| I was also wondering whether it's possible that stylesheets (DSSSL or
| XSL) might be dependent on a minimum minor revision (e.g. requiring
| DTD version 4.7 or greater), or should the only dependency they have
| be on the major revision (e.g. requiring version 4 of the DTD)?

I've tried to make the stylesheets support all versions of the DTD.
Most of our backwards incompatible changes have, in fact, been fairly
minor.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com>      | The irrational is not necessarily
http://www.oasis-open.org/docbook/ | unreasonable.--Sir Lewis Namier
Chair, DocBook Technical Committee |