There's a "keyboard shortcuts" item that's listed in the "Support" menu. When you click it, it opens a new tab to https://www.reviewboard.org/docs/manual/2.5/users/reviews/reviewing-diffs/#keyboard-shortcuts That's useful, but I feel this would be more useful if it just displayed in-page as an overlay, which can be closed by just clicking outside of the overlay. I also like how Treeherder handles this. When you press the '?' key any time that an input field is not focused, it pops up the keyboard shortcut overlay.