I just took a look inside lisp/ dir.

modula2.el overrides C-c <letter> keybindings (and so it is a bug).

All else look good (inf-lisp.el and sgml-mode.el do have a non-default-on
switch to give
C-c <letter> bindings).

There are more than a few non-standard elisp packages (@ELL or emacs-wiki)
that
are not aware of the C-c <letter> convention, I'm sure.
I guess I'll stick with not using C-c prefix for now.


On Sun, Jan 17, 2010 at 7:38 AM, Chong Yidong <cyd@stupidchicken.com> wrote:

> Deniz Dogan <deniz.a.m.dogan@gmail.com> writes:
>
> > 2010/1/17 Ken Hori <fplemma@gmail.com>:
> >>
> >> C-c prefix is supposed to be "reserved" for end-users.
> >> But the sad reality is that more than several major-modes
> >> break the convention by overriding C-c ... . So I no longer
> >> use C-c prefix and instead define my own keymap.
> >> It is more secure, at least probabilistically speaking.
> >>
> >
> > I don't think any major mode I know of binds "C-c <letter>". Note that
> > by <letter> I mean e.g. "C-c i", "C-c a", etc., not "C-c C-i" or "C-c
> > C-a".
>
> Indeed.  If you find any major mode that binds C-c <letter>, it is a
> bug, so please report it.
>