By default the key sequence Ctrl-Alt-Escape allows for escaping from a Wait pause and from a locked ModuleSynchronous command. The EscapeFunc command used with the Key command allows for configuring this key sequence. An example:

Key Escape A MC -
Key Escape A  S EscapeFunc

replaces the Ctrl-Alt-Escape key sequence with Shift-Escape for aborting a Wait pause and ModuleSynchronous command. EscapeFunc used outside the Key command does nothing.