info+man: should "Diagnostics" be replaced by "Exit Status"?

[Charles Levert]

Both the info and man documentation have
a "Diagnostics" section.  This section is
traditionally used to list and explain specific
warning and error messages.

The "Exit Status" section, in contrast, usually
documents just that, and only that.

In grep's documentation, the former title is
used above the latter content.

So, should the "Diagnostics" title be replaced
by an "Exit Status" title?

And, for _after_ the current round of
documentation restructuring, is there any
need for an actual "Diagnostics" section,
beyond the obvious?  Think about messages like
"Is a directory" that were a recent subject
of discussion.  Is this a good thing to do, or
should improving the messages themselves have
higher priority?