2.1.1 Keyboard
All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user’s movement and not just the endpoints.
NOTE: This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input but the underlying function (text input) does not.
NOTE: This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.