> We don't document every function in the manual: that would make the
> manual too large (it already prints as 2 very thick volumes). This
> function is new, and has no callers inside Emacs, so whether it is
> important enough to warrant a place in the manual remains to be seen.
> For discoverability, we rely on built-in Help features such as
> 'apropos', and yes, on people reading NEWS when they start using a new
> version, because reading that will tell them about changes in a much
> more efficient way than the same information buried among many
> hundreds of pages of the manual.
OK. Going forward, how are end users to know which functions have not
been documented on purpose and which have not been documented due to
oversight? It might be worth considering adding to future NEWS, when
a new function or variable is added, a some brief note saying that
"this function/variable will not (yet) be documented in one of the
manuals." Without that, it is impossible for a user to know whether
the lack of documentation is intentional or an error to be reported here.