On Jun 10, 2019, at 9:23, Stefan Kangas <stefan@marxist.se> wrote:

Eli Zaretskii <eliz@gnu.org> writes:

IMO, being able to bind C-[ to something else is not an important
feature, not enough to break the compatibility.  But that's me.

Perhaps it makes sense from a compatibility standpoint, but I
suspect that many users would be surprised by the inability to
rebind C-[ or C-i.  (Binding C-i also rebinds TAB.)

Would it make sense to show a warning when trying to bind keys such as
C-[ or C-i?  (Or, perhaps better, to show it in the "*Help*" buffer?
C-h k C-[ only shows "ESC- " when I try, though.)

Would it make sense to introduce a variable to turn this behaviour off
in a graphical environment?  The default could stay as is.