Policy on backwards incompatible changes

[Norman Walsh <ndw@nwalsh.com>]

/ "Bob Stayton" <bobs@sagehill.net> was heard to say:
| 7.  Policy for backwards compatible changes.

Our old policy was very strict.

* A point release (X.1,X.2,X.1.2, etc.) MUST NOT contain any backwards
  incompatible changes.

* A major release MAY contain backwards incompatible changes if and only
  if they were announced in the release notes for the previous major
  version

By these rules, DocBook V5.1 can not contain any backwards
incompatible changes. If we discover any backwards incompatible
changes that we feel should be made, they must be announced in V6.0
and can only then be made in V7.0.

It was suggested at the last telcon that perhaps these rules are too
strict for the internet age.

I dunno. There's a tradeoff to be made between DocBook's great
stability and the desire to incorporate the latest ideas.

Partly, I think we feel uncomfortable with the current rules because
V5.0 took *a very long time* to produce. I don't expect future versions
to take that long.

But even if we imagine that we'll get new major releases out
more-or-less once a year, then a 1-3 year wait for a backwards
incompatible change doesn't seem too onerous. But maybe that's too
long too.

After giving it some thought, the following proposal seems like
something I could live with:

* A point release (X.1,X.2,X.1.2, etc.) MUST NOT contain any backwards
  incompatible changes.

* A major release MAY contain backwards incompatible changes if both
  of the following conditions are true:

  - The change was announced in the release notes for the previous 
    version (major or minor)

  - The change was announced in a release that occurred at least six
    months previously.

By these rules, we can announce, in V5.1, our plans to make a
backwards incompatible change in V6.0. Then, in V6.0, if it's been at
least six months since V5.1 was released, we can make the change.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com>      | If you are losing your leisure,
http://www.oasis-open.org/docbook/ | look out! You may be losing your
Chair, DocBook Technical Committee | soul.--Logan Pearsall Smith

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