A good commit message makes reviewing your changes later easier, and is especially helpful when the release wrangler is ensuring that the version history is complete.

A commit message should have:

*:The GitTrac ticket number, in the form #123.  Note that you cannot have a "#" at the start of a line; Git will think it's a comment.  Common techniques include putting the comment at the end of the line, or enclosing it in parenthesis like (#123), or putting it in a gliss.  If multiple tickets are involved, feel free to list them all.  If zero tickets are involved, consider creating a ticket so people have a place to discuss the change and a convenient place to point to for all relevant information.
*:: Why? This number makes correlating the version history easier (assuming you include the ticket number in a comment in the version history like you should).  It also means that the ticket can include links to the relevant commits.

*:A brief description of what you changed.

*:Optionally, some extended discussion on what you changed, if you think it useful.

*: Remember to update the {wiki: VersionHistoryHowTo Version History!}. If you are confident that this change should not be mentioned in the version history, include a brief note explaining why - for instance, is it entirely invisible to the user (internal cleanup) or does it fix a bug that was never released?

*: When you are ready to push your changes back to the central repo via git push, be certain to read and follow our GitPushChecklist