RE: how to extend `C-x 8` keymap?

["Drew Adams" <drew.adams@oracle.com>]

> + (define-key iso-transl-ctl-x-8-map "d" [?d])
> + (define-key iso-transl-ctl-x-8-map "D" [??])
> 
> I get Debugger entered--Lisp error:
> (void-variable iso-transl-ctl-x-8-map)

Oh, right.

You should be able to do the same thing, but quoting the keymap var (actually, a
function that DTRT):

(define-key 'iso-transl-ctl-x-8-map "d" [?d])
(define-key 'iso-transl-ctl-x-8-map "D" [??])
            ^
            |
            +-- quote mark

If that doesn't work then try this before using the unquoted sexps:

(require 'iso-transl)