Yes, there area few examples from Voyager. Janeway uses the code "Janeway-Pi-1-1-0" in the season 2 episode 17, "Dreadnought:" > JANEWAY: Computer, initiate the self-destruct sequence. Authorisation Janeway pi one one zero. Set it at twenty minutes. and then again a few episodes later in season 2 episode 21, "Deadlock": > JANEWAY 2: Move it, Ensign! That's an order! Computer, initiate the self-destruct sequence. Authorisation Janeway pi one one zero. Set at five minutes and mute voice warnings. Enable.