Variable: comment-auto-fill-only-comments
comment-auto-fill-only-comments is a customizable variable defined in
newcomment.el.gz.
Value
nil
Documentation
Non-nil means to only auto-fill inside comments.
This has no effect in modes that do not define a comment syntax.
Probably introduced at or before Emacs version 26.1.
Source Code
;; Defined in /usr/src/emacs/lisp/newcomment.el.gz
;;;###autoload
(defcustom comment-auto-fill-only-comments nil
"Non-nil means to only auto-fill inside comments.
This has no effect in modes that do not define a comment syntax."
:type 'boolean
:group 'comment)