bug#23171: 25.0.92; Key binding conventions for all modifiers

[Philipp Stephani <p.stephani2@gmail.com>]

Am Fr., 8. Nov. 2019 um 14:06 Uhr schrieb Eli Zaretskii <eliz@gnu.org>:
>
> > From: Stefan Kangas <stefan@marxist.se>
> > Cc: Eli Zaretskii <eliz@gnu.org>,  23171@debbugs.gnu.org
> > Date: Fri, 08 Nov 2019 05:51:38 +0100
> >
> > Philipp Stephani <p.stephani2@gmail.com> writes:
> >
> > > Eli Zaretskii <eliz@gnu.org> schrieb am Do., 31. März 2016 um 21:26 Uhr:
> > >
> > >  > From: Philipp Stephani <p.stephani2@gmail.com>
> > >  > Date: Thu, 31 Mar 2016 19:40:25 +0200
> > >  >
> > >  > The manual entry "Key binding conventions" talks only about a small
> > >  > subset of possible key bindings, such as the C-c prefix and the function
> > >  > keys.  Keys with Meta, Super, Hyper, and Alt are not documented.  The
> > >  > manual should contain conventions/rules for all possible keys.
> > >
> > >  I'm not sure I understand the essence of the report.  There's a whole
> > >  section (named, unsurprisingly, "Key Bindings") dedicated to key
> > >  bindings, and a subsection there named "Modifier Keys" covers all the
> > >  modifiers, AFAICT.
> > >
> > > What I mean is a specification which combinations are reserved for the user, minor modes, and major modes. Context is
> > > http://debbugs.gnu.org/cgi/bugreport.cgi?bug=22604, where such an addition was requested for C-c combinations. Here I request
> > > one for all keys.
> >
> > Which conventions are we talking about here more specifically?  Could
> > you enumerate them or give a couple of examples?
>
> FWIW, I don't see any need for any further specifications.  The manual
> says what keys to reserve; all those which aren't mentioned, including
> with modifiers, aren't reserved.

What does it mean for a key sequence to be unreserved? Anybody can use
it for any purpose? If so, how do we prevent clashes between these
unreserved sequences?