Man: "I think I found your briefcase."
Frasier: Oh, really? Really, are you sure?
Man: "Man: Pretty sure."
Frasier: Well, there's a way we can be positive. Simply turn over the briefcase and in the upper right-hand corner you should find a half-moon-shaped watermark, such as would be left by the careless resting of a champagne flute.
Man: "It's full of your stuff, Dr. Crane."
Frasier: Oh. Well, that works as well, yes.