It should be possible to comment on an entire file
Proposal
Currently it is not possible to comment on an entire file, you need to associate a comment to a line. It should be possible to comment on a whole file, e.g. to suggest a find/replace of a term that's used widely rather than suggest on each instance.
I tried searching for an existing issue, but didn't find one that was clearly the same. Found the following via Google:
Edited by Ian Pedowitz