A touch of Vertigo in the DC Universe
These days, the barrier between Karen Berger's Vertigo and Dan DiDio's DC Universe seems to be impenetrable. Characters from one side of the tracks don't pop up wandering the other, period. Every once in a while, though, someone surprising manages to sneak through.
Ever hear Matt Wagner's story about how he got away with including bits of DC Universe in his Madame Xanadu series for Vertigo? Every time he includes one in his script, his editor tells him that he needs to ask for the OK from the higher-ups. Wagner goes and asks, and permission is denied. He tells his editor that it's been okayed and he has permission. The editor allows it in. When the issue is published, nobody notices his transgression.