Need of maintaining unsupported release notes in HEAD?

Hi All,

From the latest HEAD code, I observed that we are still updating the
unsupported
versions of the release notes sgml files. I can understand that these
supported
version files are required for easier back-branch releases.

I vaguely remember that some one bring up this discussion some time ago,
but I am not able to find those details. I didn't find any need of these
older release
notes in the HEAD, I doubt that any one refers them. Is there any specific
reason exist for these unsupported version release notes files?

Following is a git log of release-9.1.sgml update on today's HEAD:

578b229718 Remove WITH OIDS support, change oid catalog column visibility.
e568eed2fc doc: Fix links to pg_stat_replication
3c49c6facb Convert documentation to DocBook XML
1ff01b3902 Convert SGML IDs to lower case
c29c578908 Don't use SGML empty tags
1c53f612bc Escape < and & in SGML
9ed74fd463 doc: update markup for release note "release date" block
50c956add8 Remove createlang and droplang

Attached patch removes all the older release notes sgml files from HEAD.
And also going forward, how about removing one major version file whenever
that is unsupported from HEAD?

comments?

Regards,
Haribabu Kommi
Fujitsu Australia