> IIRC you can use
>
>     (let* ((doc (documentation NAME))
>            (fd (help-split-fundoc doc NAME)))
>       (if fd (cdr fd) doc))

Obviously, but at that point it's not cleaner (or clearer) than simply calling a function that does replace-regexp-in-string, IMO.

> Maybe it should always return a pair (USAGE
> . DOC) so we could just do:
>
>     (cdr (help-split-fundoc (documentation NAME) NAME)

I'm not against it, but that's changing the behavior of a non-internal function (it's already used like ten times just in our sources) which has been like that for at least six years, likely more.