Yes, it should say what it's for, but it shouldn't need to explain itself any further. Sorry if I didn't make that clear. For example, if someone refactored s

Yes, it should say what it's for, but it shouldn't need to explain itself any further. Sorry if I didn't make that clear. For example, if someone refactored something, the commit log can simply say "Factorize foo", it need not explain why they were refactoring in the first place.