Suites Password Reminder is a miscellaneous item in the Fallout: New Vegas add-on, Dead Money.
It can be found in the suites area of the Sierra Madre.
Make sure to set a separate security override for the hallway loudspeakers before you leave tonight. The last thing we need is our coms going down in the middle of a robbery. Set it to 1837uC@n7Gu355. That should prevent a lucky guess by some hack with a stolen security card.