Forum OpenACS Improvement Proposals (TIPs): Re: TIP #46: (Proposed) Rules for Version Numbering and CVS tagging of Packages
One wrinkle though, the change to support rcN in versions requires a change to the plsql proc which compares version numbers, which means there needs to be an upgrade script. That upgrade will be a little tricky since you will need to upgrade the plsql proc before you go out to figure out which scripts to run (i.e. to upgrade you need to upgrade...).
Re Joel's last question, I'm afraid that this would indeed create problems with old installations.
We should go ahead and make the SQL function that determines this right away, so we get this new feature into the installed base as quickly as possible.
But we should not rely on it until we have determined, tested, and verified a solution that works for older installs as well.