Variable: bookmark-version-control
bookmark-version-control is a customizable variable defined in
bookmark.el.gz.
Value
nospecial
Documentation
Whether or not to make numbered backups of the bookmark file.
It can have four values: t, nil, never, or nospecial.
The first three have the same meaning that they do for the
variable version-control; the value nospecial (the default) means
just use the value of version-control.
Source Code
;; Defined in /usr/src/emacs/lisp/bookmark.el.gz
(defcustom bookmark-version-control 'nospecial
"Whether or not to make numbered backups of the bookmark file.
It can have four values: t, nil, `never', or `nospecial'.
The first three have the same meaning that they do for the
variable `version-control'; the value `nospecial' (the default) means
just use the value of `version-control'."
:type '(choice (const :tag "If existing" nil)
(const :tag "Never" never)
(const :tag "Use value of option `version-control'" nospecial)
(other :tag "Always" t)))