I have drafted http://fedoraproject.org/wiki/PackagingDrafts/CommitIDs and added it to the schedule. The proposal is simply to add the following text to the naming guidelines to the "Snapshot packages" section:

If the upstream revision control system provides some sort of unique commit identifier, it may be appended to the `%{alphatag}`: {{{ YYYYMMDDsvn12345 YYYYMMDDgit5aef11739b }}}

This has been in use for a while in a few instances, so it would be good to consider it officially.

- J<