33.2.2 Keymaps and Minor Modes

Each minor mode can have its own keymap, which is active when the mode is enabled. To set up a keymap for a minor mode, add an element to the alist minor-mode-map-alist. See Active Keymaps.

One use of minor mode keymaps is to modify the behavior of certain self-inserting characters so that they do something else as well as self-insert. In general, this is the only way to do that, since the facilities for customizing self-insert-command are limited to special cases (designed for abbrevs and Auto Fill mode). (Do not try substituting your own definition of self-insert-command for the standard one. The editor command loop handles this function specially.)