  <> ^ C - K E Y B O A R D  I N T E R R U P T <>

Interrupts lengthy commands that are not otherwise interruptible, currently
Y-CHANGEALL, command files that have been invoked by U-USE, and macros that call
one another (the interruption occurs when one macro tries to call another).
Also, inputting of a file can be interrupted (i.e. Q-QUIT with a filename or
E-ENTER or when just starting). At other times it has no effect except that if
typed as the only character in a command it has the same effect as the K
command.

Q expects the interrupt character to be ^C but tolerates ^P as an alternative.
Use of any other character may result in some feature being unavailable.
