Variable: jit-lock-mode
jit-lock-mode is a buffer-local variable defined in jit-lock.el.gz.
Documentation
Non-nil means Just-in-time Lock mode is active.
Probably introduced at or before Emacs version 21.1.
Source Code
;; Defined in /usr/src/emacs/lisp/jit-lock.el.gz
;;; Variables that are not customizable.
(defvar-local jit-lock-mode nil
"Non-nil means Just-in-time Lock mode is active.")