If you press escape while adding a note or comment to a ticket, it closes the note/comment and erases everything you had written. Personally, I think shortcut keys should be reserved for repetitive actions and don't think "cancel" needs a shortcut key. At the very least, it should prompt you to confirm that you want to cancel your comment/note instead of just deleting it outright.
I have multiple monitors with several applications open at any given time and accidentally pressed escape while my cursor was focused on a particularly long comment I was writing - lost everything.
