reveal-mode
reveal-mode is an interactive autoloaded compiled Lisp function in `reveal.el
'.
(reveal-mode &optional ARG)
Toggle uncloaking of invisible text near point (Reveal mode).
With a prefix argument ARG, enable Reveal mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
Reveal mode if ARG is omitted or nil.
Reveal mode is a buffer-local minor mode. When enabled, it
reveals invisible text around point.