The Trouble With Tribbles - S2-E15
Visible crew/equipment: After Mr. Baris takes Darvin into custody and leaves the room, when Kirk walks over to Captain Koloth three white tape marks are visible on the floor. (00:45:10)
The Trouble With Tribbles - S2-E15
Visible crew/equipment: After Mr. Baris takes Darvin into custody and leaves the room, when Kirk walks over to Captain Koloth three white tape marks are visible on the floor. (00:45:10)

Visible crew/equipment: After McCoy examines Charlie and they talk about how Charlie learned to talk by just listening to the ship's tapes, when Charlie stands up the two actors' marks can be seen on the floor - the short one for Charlie and the longer one for McCoy, where they both will stand momentarily. (00:04:56)
Who Mourns for Adonais? - S2-E2
Trivia: An ending that was planned but abandoned for this episode would have revealed that Lieutenant Palamas was pregnant with Apollo's child.
The Corbomite Maneuver - S1-E11
Question: At the beginning, Mr Sulu calls for Captain Kirk to report to the bridge, but Kirk in sick bay does not get that message. Why?
Answer: Kirk was getting his physical and Dr. McCoy probably turned off communications, because if he hadn't, Kirk would have left and headed straight for the bridge, leaving McCoy irritated.