From Fedora Project Wiki

Proposal: ammend http://fedoraproject.org/wiki/Packaging/NamingGuidelines to allow the maintainer to choose the form of for commit IDs to be used for snapshot packages where the upstream VCS allows them. This has been used in practise for a while, so it would be good to officially allow it in the guidelines.

Change:

If a snapshot package is considered a "pre-release package", you should follow the guidelines listed in Pre-Release Packages , and use an %{alphatag} in the following format:

YYYYMMDDcvs

Where YYYY is the digits for the year, MM is the zero-padded digits for the month, DD is the zero-padded digits for the day, and "cvs" is the type of checkout. The date in reference is the date that the checkout was taken.

To:

If a snapshot package is considered a "pre-release package", you should follow the guidelines listed in Pre-Release Packages , and use an %{alphatag} beginning with the date in YYYYMMDD format and followed by up to 16 (ASCII) alphanumeric characters of your choosing. The date should reference the date the checkout was taken; the rest can be as simple as "cvs" or "snap", or a subversion change number like "svn12345" or an abbreviated git hash like "git5aef11739b".