bug#17362: 24.4.50; inconsistent key notation: `ESC' vs `<ESC>'

[Drew Adams]

>     - If a key does not have a label, its name should be in all caps,
>       as in @key{TAB} or @key{META}.
> 
>     - There are 2 exceptions to the last 2 rules, both for historical
>       reasons:
> 
>       * @key{BACKSPACE}, although many keyboards have a "Backspace"
>         label on it.
> 
>       * @key{ESC}, which is labeled "Esc".

Eli, are you saying that you have replaced <delete>, <backspace>, etc.
everywhere with <DELETE>, <BACKSPACE>, etc., or that you think it is
appropriate to do so?

Seems like that would be a big change from the past and a change from
how Emacs itself communicates with users.  AFAIK, Emacs writes <delete>
for the Delete key etc.  The rule for function keys and pseudo function
keys has always been to use lowercase (in angle brackets), no?

I thought that we used uppercase only for the ASCII control chars: TAB,
RET, ESC, and DEL, and not for key sequences involving pseudo function
keys <tab> and <backspace>.  (I also thought that we specifically did
NOT enclose the former in angle brackets, but I guess that's another
story.)

You will perhaps say that <TAB> refers only to the keyboard key, and
not to an Emacs key sequence.  In that case, it should not appear as
part of a key sequence notation, IMO.

And I would have thought that the keyboard keys would anyway be
written the same as they are on the keyboard: Tab, Backspace, Delete,
Esc, not <TAB>, <BACKSPACE>, <DELETE>, <ESC>.

It seems to me that:

1. The way Emacs talks to users, via `kbd', `edmacro-parse-keys', and
   help output in general should not be changed.

2. The doc (manual) should follow the same conventions as `kbd',
   `edmacro-parse-keys' and help output in general.

I am more concerned about #1 than #2.  I don't actually see you
proposing any change wrt #1 so far, which is good.

I do not, however, see a good reason why Emacs doc (manuals) should
represent key sequences differently than Emacs help does.  That kind
of goes against Occam's razor, multiplying things unnecessarily.

Let me know if I am misunderstanding something.  I admit to feeling
a bit confused now by the various notations.  I thought it was pretty
straightforward: just ASCII control char names (uppercase), function
keys and pseudo function keys (lowercase, in angle brackets).  It no
longer seems so straightforward and simple.