Variable: mode-line-position-column-format
mode-line-position-column-format is a customizable variable defined in
bindings.el.gz.
Value
(" C%c")
Documentation
Format used to display column numbers in the mode line.
This is used when column-number-mode(var)/column-number-mode(fun) is switched on. The
"%c" format spec is replaced by the zero-based column number,
and "%C" is replaced by the one-based column number.
Also see mode-line-position-column-line-format.
This variable was added, or its default value changed, in Emacs 28.1.
Probably introduced at or before Emacs version 28.1.
Source Code
;; Defined in /usr/src/emacs/lisp/bindings.el.gz
(defcustom mode-line-position-column-format '(" C%c")
"Format used to display column numbers in the mode line.
This is used when `column-number-mode' is switched on. The
\"%c\" format spec is replaced by the zero-based column number,
and \"%C\" is replaced by the one-based column number.
Also see `mode-line-position-column-line-format'."
:type '(list string)
:version "28.1"
:group 'mode-line)