In the description, second paragraph, it says that J! shared the Studio 3 space with The Tonight Show Starring Johnny Carson. Actually, at least as of 1985, Carson was taped in Studio 1, which is next door to 3 (Studios 2 and 4 are elsewhere in the building, and were mostly used for local programming IIRC). The first few episodes of Jay Leno were taped in 1 as well, but that did switch over to Studio 3.