customize-changed-options is an interactive autoloaded compiled Lisp function in `cus-edit.el'.

It is bound to <menu-bar> <options> <customize> <customize-changed-options>.

(customize-changed-options &optional SINCE-VERSION)

Customize all settings whose meanings have changed in Emacs itself.
This includes new user options and faces, and new customization
groups, as well as older options and faces whose meanings or
default values have changed since the previous major Emacs

With argument SINCE-VERSION (a string), customize all settings
that were added or redefined since that version.