Optional callback function. If present, OllyDbg calls it each time when user presses combination of keys that is not recognized by standard OllyDbg window. This function is usually called twice: first time with origin=PM_MAIN indicating global shortcut, and second time with origin identifier of window that has keyboard focus. Shortcuts are scarce resource and I will constantly add new to OllyDbg, so use this feature with care and always implement alternative possibilities.