
Those are PRODUCTION markings.
The Big Bang Theory Season 3, Episode 17

Well, Penny is on her way to perform in
a one-night showcase PRODUCTION of Rent...
The Big Bang Theory Season 1, Episode 10

...to inadequate serotonin PRODUCTION.
The Big Bang Theory Season 1, Episode 10

Yeah, they say the yeast in beer
helps with milk PRODUCTION.
The Big Bang Theory Season 10, Episode 22

That's the one thing I'm certain of,
PRODUCTION cannot stop.
Breaking Bad Season 3, Episode 13