This tip just popped up in my phpStorm IDE (OS X):
The ⎋ key in any tool window moves the focus to the editor. ⇧⎋ moves the focus to the editor and also hides the current (or last active) tool window. The F12 key moves the focus from the editor to the last focused tool window.
I've never seen that key symbol before and Google returned nothing.
Anybody know the meaning of this mysterious key?