bug#15917: 24.3.50; manual: mention keys reserved for users

[Stefan Kangas]

Drew Adams <drew.adams@oracle.com> writes:

>> >> +Key sequences that consist of @kbd{C-c} followed by a letter (upper or
>> >> +lower case) are ``reserved for users,'' and will never conflict with
>> >> +any properly designed Emacs extension or Emacs itself.
>> >
>> > IMO that last part ("will never conflict")
>> > sounds too automatic or passive.
>>
>> How about "should not conflict"?  Otherwise, please propose an
>> alternative.
>
> Better, yes.  But that could mean that we expect that,
> most of the time, they won't (automatically).

I don't understand the second sentence.  Could you please elaborate?

> Active voice here removes such ambiguity, I think.
>
>   Key sequences that consist of @kbd{C-c} followed by a
>   letter are reserved for users.  Please do not write
>   code to be used by others that binds these keys.

Such advice is already in the elisp manual.  The user manual should
rather advice users which keys are reserved for their use in their Init
file.  So I don't think writing about "code to be used for others" is
suitable here.

> (Why mention "upper or lower"? Why put "reserved for users"
> in quotes?)

We can probably remove that, yes.