Variable: kept-old-versions
kept-old-versions is a customizable variable defined in files.el.gz.
Value
2
Documentation
Number of oldest versions to keep when a new numbered backup is made.
See version-control for how Emacs decides when to make numbered backups.
Probably introduced at or before Emacs version 17.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defcustom kept-old-versions 2
"Number of oldest versions to keep when a new numbered backup is made.
See `version-control' for how Emacs decides when to make numbered backups."
:type 'natnum
:safe #'natnump
:group 'backup)