Emacs: Show Form Feed as Line
Displaying Form Feed Character as Line
Emacs lisp uses the Form Feed character (Form Feed; U+0C) as source code section marker. It is displayed as “^L”.

Here's a command to display the Form Feed character as a line.
(defun xah-show-formfeed-as-line () "Display the formfeed ^L char as line. URL `http://xahlee.info/emacs/emacs/emacs_form_feed_section_paging.html' Version 2018-08-30" (interactive) ;; 2016-10-11 thanks to Steve Purcell's page-break-lines.el (progn (when (not buffer-display-table) (setq buffer-display-table (make-display-table))) (aset buffer-display-table ?\^L (vconcat (make-list 70 (make-glyph-code ?─ 'font-lock-comment-face)))) (redraw-frame)))
Insert Form Feed Character
To insert form feed character, press Ctrl + q then Ctrl + l.
[see Emacs Key Syntax Explained]
Move Cursor to Prev/Next Formfeed
Move cursor to the prev/next page break:
forward-page
【Ctrl + x ]】backward-page
【Ctrl + x [】
You can set a more easy key that can be held down:
;; keys for moving to prev/next code section (Form Feed; ^L) (global-set-key (kbd "<C-M-prior>") 'backward-page) ; Ctrl+Alt+PageUp (global-set-key (kbd "<C-M-next>") 'forward-page) ; Ctrl+Alt+PageDown
Using Ctrl + Alt makes it consistent with the default keys to navigate lisp code. [see Emacs: How to Edit Lisp Code]
For a detailed discussion of using the Form Feed character as page section marker, see: Emacs Form Feed ^L.
Thanks to Steve Purcell ( [2012-11-14 https://twitter.com/sanityinc ] ) for his page-break-lines.el package.