1 Luke: What’s that?
1 Han: Hands off, kid. That’s the on/off switch.
2 Luke: And what’s that?
3 Han: It toggles between encryption codes for communicating with either the leader of the Rebel Alliance, or the Death Star commander.
4 Luke: You mean...
4 Han: It’s the Mon/Moff switch.

This was an ancient note in my ideas file, submitted by a reader many years ago, I think.

For those who need assistance: Mon, Moff.