RE: [External] : The `^L' appeared in built-in help.

[Drew Adams]

> Any hints for this phenomenon?

A form-feed char (Control L) has from the outset
been used as an ASCII control character, to cause
a new page to be advance (fed) on old printers.

Emacs leverages this old meaning by using it as
a page separator, for <whatever> meaning of "page".
Emacs has page-movement commands that make use of
this character, just as it has line-oriented
commands that make use of line ending chars such
as newline.

Try `C-x ]'.

See the Emacs manual, node Pages:

https://www.gnu.org/software/emacs/manual/html_node/emacs/Pages.html

`C-h r' is your friend, along with his buddy, `i'.
`C-h r i page TAB', then choose a completion such
as `pages' or `page-delimiter'.