Who has ever seen one of the broadcast networks "slip up" and accidentally broadcast something meant to be seen or heard only by the affiliates and not by the general public? You know -- test patterns, slides, slates, countdowns, or any audio voice-overs.I've already mentioned in a prior thread the apparent internal announcement on NBC that aired the day of the 1977 NYC Blackout -- the one with the techie announcing the start time of the delayed "Tonight Show" for the benefit of the affiliates. Stuff like that.One example I witnessed many years ago doesn't quite fit my own parameters above, but it was definitely something not meant to be seen nationally at any rate. NBC once cancelled a couple of prime-time shows on very short notice (this would have been during the "Supertrain" era when their shows were dying like flies left and right) and substitued a movie in their place. (It was the perfectly horrible "Rafferty and the Highway Hustlers" with Sally Kellerman, Alan Arkin, and a young pre-"One Day at a Time" Mackenzie Phillips.) Someone slipped up on the timing, because the movie ran a good 5 or 6 minutes short in the time slot. The credit roll finished, followed by a short period of dead air, and then nationwide viewers were treated to a series of local PSAs and promos, all with the WNBC-TV New York logo clearly included on each one!!I suppose in the panic of realizing they were going to run short, the techies in NY just grabbed whatever was at hand and ran with it. 