CKEditor keystroke configuration is numeric. Each keystroke consists of array of two elements: the keystroke number, and the command to execute. The calculation of the number requires an addition of ASCII codes of characters and special numbers for Ctrl, Alt, and Shift. For example, a key 'F1' that executes 'help' is normally configured as "[ 112, 'help' ]".
Hippo CKEditor configuration should also support a more declarative keystroke style, where the various keys in a keystroke are represented as separate string elements in a keystroke configuration array. For example, the keystroke 'Ctrl-Alt-H' that executes 'help' could be represented a "['Ctrl', 'Alt', 'h', 'help' ]".