bug#60930: 30.0.50; 24.3 Choosing File Modes section of Emacs manual does not explain dealing with backup files

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: 60930@debbugs.gnu.org
> Date: Thu, 19 Jan 2023 13:35:08 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> As for discoverability, an index entry might do.
> >
> > Please suggest a useful index entry.
> 
> choosing a major mode, in backup files
> choosing a major mode, in encrypted files

Thanks, I added

  @cindex backup files, choosing a major mode
  @cindex encrypted files, choosing a major mode

because it is not useful to add several index entries that begin with
the same text and point to the same place.  If you think how index
entries are used, you will understand why.

P.S.  I'm not sure index entries will help discoverability (you need
to know what you are looking for to type an index entry), but adding
indexing can never do any harm.