Štěpán Němec wrote:

:-) I was actually considering just that, so I'm glad you mention it.

I can try to compile an initial version of such a document, based on the
commit message of the original single-patch version
(<http://article.gmane.org/gmane.comp.version-control.git/158467>) and
including some more cases/examples.

Where do you think would be the most appropriate place for it?
Just add a section to CodingGuidelines, or a separate
Documentation/WritingGuidelines or something?

Sorry for the slow response.  Documentation/CodingGuidelines makes sense
to me, since it affects the usage strings in code.