The Return of Major Bonacelli - S4-E25
Revealing mistake: When Hogan, Carter and Le Beau are talking to Schultz, you can see it is an overcast day. After Hochstetter comes in and the camera cuts to them talking about Bonacelli, it goes back to Hogan. You can now see that they are on a sound stage. The reasons are that the guard isn't moving in The Tower, the boys are well lit, and as Hogan and Le Beau go into the barracks, you can see differences in the painting of the sky on the back drop.
The Return of Major Bonacelli - S4-E25
Continuity mistake: Klink poses for a picture in quarter profile of the right side of his face for Bonacelli, who is actually getting a shot of the guns. Later, you see the picture, and Klink is fully facing the camera.
The Return of Major Bonacelli - S4-E25
Continuity mistake: When Klink is insisting on talking to the cook, Bonacelli has his hands clasped in front of his plate. When the angle changes, his hands are down on wither side of his plate.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.