An Actor Allusion is a joke or reference which is specific to one of the actors in a show. It can be a little blink-and-you'll-miss-it moment, such as Mary Albright (Jane Curtin) spotting some people in Conehead costumes at a sci-fi convention in 3rd Rock from the Sun, or it can be bigger and more blatant, such as when John Lithgow repeated his entire anti-music rant from Footloose in the same show.