RE: file path in buffer name

[Drew Adams]

> There are some 7000 options in bare Emacs. I do not believe all
> of them are in the manual.

All of them? Let's see.

Is every option that is in the manual in its Variable Index? I'm guessing yes
(modulo indexing bugs).

Is every variable that is in the Variable Index an option? No; the second one
listed, `abbrev-file-name', is a counter example.

How many variables are there in the Variable Index? 786 (`M-x what-line' shows
there are 795 lines, minus 9 for the intro text.)

So if there are ~7000 options at startup time, maybe ~10% are in the manual.
Yes, certainly far from all.

Some options are no doubt documented in the Elisp manual, instead. But there
there is no division of that index by object type (e.g. variable vs function),
so there is no easy way that I'm aware of to count them.