outline-minor-modeをhowmと一緒に使いたいことが多いのですが、いつもキーバインドを忘れてしまうので、ここにメモしておきます。
`outline-minor-mode' Minor Mode Bindings Starting With C-c C-o:
key binding
--- -------
C-c C-o C-a show-all
C-c C-o C-b outline-backward-same-level
C-c C-o C-c hide-entry
C-c C-o C-d hide-subtree
C-c C-o C-e show-entry
C-c C-o C-f outline-forward-same-level
C-c C-o TAB show-children
C-c C-o C-k show-branches
C-c C-o C-l hide-leaves
C-c C-o RET outline-insert-heading
C-c C-o C-n outline-next-visible-heading
C-c C-o C-o hide-other
C-c C-o C-p outline-previous-visible-heading
C-c C-o C-q hide-sublevels
C-c C-o C-s show-subtree
C-c C-o C-t hide-body
C-c C-o C-u outline-up-heading
C-c C-o C-v outline-move-subtree-down
C-c C-o C-^ outline-move-subtree-up
C-c C-o @ outline-mark-subtree
C-c C-o C-< outline-promote
C-c C-o C-> outline-demote