This is when a writer uses strong continuity in his or her comics, but frequently when it is in reference to something (a work or a creation) that THAT writer did in the past.

Chuck Dixon was big on this, having minor characters from one of his four Bat-books show up constantly in his other Bat-books.

The funniest point of Dixon's nepotistic continuity history is when he had the clone of Guy Gardner (that he had introduced during a very short run on Guy Gardner: Warrior) show up in Birds of Prey.

NOTE: I am not saying that this is a BAD thing.