If you’ve made a lot of changes to REAPER’s keyboard shortcuts, you might find it helpful to have a printed list to reference. REAPER actually has this feature built in with an auto-generated html list.

All you need to do is press Shift+F1 (+ function key maybe on Apple keyboards) which will create the list of all the currently assigned actions, and open the html file in your default browser. You can then save this as a pdf, or send it to your printer.

Note: use Preferences/Editing Behavior/Mouse Modifiers to add or change any of the following mouse key modifiers.