?, are handled magically for you. They should just work.
mod+k, on Mac this ends up mapping to
command+swhereas on Windows and Linux it maps to
ctrl+k. This will allow you to trigger an action when the ctrl and k keys are pressed together Note do not use more than one character key in a combination. If you do the shortcut will be triggered by only that last key specified in the combination. You can use a sequence in that case or use the character key in combination with a special or modifier key.
shift a. Or you can even have a complex key sequence like
up up down down left right left right b a enter. You can also make a sequence that includes key combinations within it. e.g.
g o command+enter: this means that to trigger this shortcut the user has to press
gquickly followed by
oand then press