@weierophinney I considered that, but I wasn't sure if someone might want to respond with a sort of "everything's OK, but things didn't quite go down like you might have expected" kind of error.  For example, if someone wants to delete something that's not there.  Is that a success or an error?  What they want is gone, so it might be fair to respond with a success code, but a message that indicates the fact that the resource they were asking about wasn't actually found in order to delete.

Whatever the case, I think my own usage of this will be fine without the non-problem codes.