When was the last time that this caption was placed prior to the start of a television program?

I dunno but I have always preferred MONO :)

It can still be seen on some of the Newhart reruns. So I'd say until around 1990.

I think The Hogan Family has that still.

So I'd say until around 1990.
Later than that, as a lot of FOX shows had it, including "The Simpsons".

CBS Saturday morning shows had a "CBS StereoSound" bug at the start until at least 1997.

im wondering what it meant

im wondering what it meant


What it means is that in the past, not all broadcasts were in stereo. So while the program maybe broadcasted in stereo by the network, your local broadcaster may not have broadcasted in stereo. Stereo sound is like a chain. Unless each and every link is in stereo you lose it.

CBS had the 'cbsstereosurround' bug in daytime at least until the early 2000s. You couldn't miss it on B&B where it appeared against a black screen in the middle with a B&B music stinger. FOX's Cops seemed to have it forever.