Matthew Perrydox 

When celebrities are referenced in one part of a fictional work, and then appear in another. Best known for Matthew Perry in the West Wing, who was referenced as a famous actor in one episode, and then guest starred as someone else in another.

The fact that Donna knew who Matthew Perry was, but didn't think Joe Quincy looked like him is a Matthew Perrydox.

Matthew Perrydox by Donna Moss December 19, 2010