Variable: mouse-buffer-menu-mode-groups
mouse-buffer-menu-mode-groups is a variable defined in mouse.el.gz.
Value
(("Info\\|Help\\|Apropos\\|Man" . "Help")
("\\bVM\\b\\|\\bMH\\b\\|Message\\b\\|Mail\\|Group\\|Score\\|Summary\\|Article" . "Mail/News")
("\\<C\\>" . "C")
("ObjC" . "C")
("Text" . "Text")
("Outline" . "Text")
("\\(HT\\|SG\\|X\\|XHT\\)ML" . "SGML")
("\\blog\\b\\|diff\\|\\bvc\\b\\|cvs\\|Git\\|Annotate" . "Version Control")
("Threads\\|Memory\\|Disassembly\\|Breakpoints\\|Frames\\|Locals\\|Registers\\|Inferior I/O\\|Debugger" . "GDB")
("Lisp" . "Lisp"))
Documentation
How to group various major modes together in C-<down-mouse-1> (mouse-buffer-menu).
Each element has the form (REGEXP . GROUPNAME). If the major mode's name string matches REGEXP, use GROUPNAME instead.
Source Code
;; Defined in /usr/src/emacs/lisp/mouse.el.gz
(defvar mouse-buffer-menu-mode-groups
(mapcar (lambda (arg) (cons (purecopy (car arg)) (purecopy (cdr arg))))
'(("Info\\|Help\\|Apropos\\|Man" . "Help")
("\\bVM\\b\\|\\bMH\\b\\|Message\\b\\|Mail\\|Group\\|Score\\|Summary\\|Article"
. "Mail/News")
("\\<C\\>" . "C")
("ObjC" . "C")
("Text" . "Text")
("Outline" . "Text")
("\\(HT\\|SG\\|X\\|XHT\\)ML" . "SGML")
("\\blog\\b\\|diff\\|\\bvc\\b\\|cvs\\|Git\\|Annotate" . "Version Control")
("Threads\\|Memory\\|Disassembly\\|Breakpoints\\|Frames\\|Locals\\|Registers\\|Inferior I/O\\|Debugger"
. "GDB")
("Lisp" . "Lisp")))
"How to group various major modes together in \\[mouse-buffer-menu].
Each element has the form (REGEXP . GROUPNAME).
If the major mode's name string matches REGEXP, use GROUPNAME instead.")