> If you simply want to comment the current state of the code, you should add a comment in the code.

I think you mean "past state of the code"...

These comments rarely get updated. My favorite recent one was several sentences describing a data structure and how it mapped out statuses, written about a decade ago. Barely a year after that comment and its code was written, the entire thing was re-written with completely different structure - and the comment left unchanged. Left a co-worker completely baffled due to inexperience with perl, we figured out what happened because of svn blame.