Remote maintenance terminal password is a paper note in the Fallout: New Vegas add-on Dead Money.
Location
It can be found in Ennis's locker in the small room, center north of the Puesta del Sol switching station map. You can find the key for the locker on one of the desks around the perimeter of the big eastern room.
Transcript
To: William Ennis
From: Konrad Simmons
Damn it, Ennis, how many times do I have to tell you? The password for the Remote Maintenance Terminal is T7GF0SEW.