Sorry, should have written Join in Progress. It mainly occurs for say breaking news or sports where there’s a rerun of a program right after. Say for the State of the Union coverage and for example the speech is supposed to end at 10:15PM and you plan 15 minutes for post analysis. But the speech runs past 10:25, so coverage would all end at 10:40, networks would typically schedule a 30 minute show at 10:30 which will dead roll. They’ll also typically schedule and dead roll a half hour program at the 10 half hour incase it ends early. Additionally say if a network loses a feed and sounds like it will be a long term loss they’ll have programs designated as floaters so they have something to start from the beginning.
Don’t let anyone treat you like you’re a VO/SOT when you’re a PKG.