Variable: 2C-mode
2C-mode is a buffer-local variable defined in two-column.el.gz.
Documentation
Marker to the associated buffer, if non-nil.
Source Code
;; Defined in /usr/src/emacs/lisp/textmodes/two-column.el.gz
;; Markers seem to be the only buffer-id not affected by renaming a buffer.
;; This nevertheless loses when a buffer is killed. The variable-name is
;; required by `describe-mode'.
(defvar-local 2C-mode nil
"Marker to the associated buffer, if non-nil.")