Other mistake: The scene in Klink's quarters is one of a few where you can see Larry Hovis' (Carter) wedding ring.
Drums Along the Dusseldorf - S3-E30
Other mistake: The fire spread from the back of the canopy to the front too quickly to be real. Therefore, it had to be soaked with an accelerator.
Funny Thing Happened on the Way to London - S3-E5
Other mistake: When Lieutenant Bauman starts speaking German, his last two words "especial mission" is said in a decidedly French accent. The correct German phrase would be "Sonderauftrag." Non-German terms like "Mission" were generally avoided in the Wehrmacht for ideological reasons.
Some of Their Planes Are Missing - S3-E2
Other mistake: While Carter starts shining boots, the disturbed stage flooring can be seen in front of the opposite building; the joint between the panels is markedly raised.
Is There a Doctor in the House? - S3-E18
Other mistake: As Carter gets ready to clean out the stove, Newkirk closes his eyes and winces just before the bellows Carter has blows.
Nights in Shining Armor - S3-E8
Other mistake: When Hogan shoots the vest, it stays still for a couple of seconds then swings in a way that is not normal.
Other mistake: Towards the end, the shot of the plane landing is a recycled shot. Even though Klink waved the flashlight, an unidentified person can be seen in the shot waving a signal light in the midst of the field. Klink was by his car.
Nights in Shining Armor - S3-E8
Other mistake: In Hogan's quarters, after Hogan reveals the two Aces up Newkirk's sleeve, Newkirk goes to brush his hair. As his hand goes up, you can see the cards in his hand.
Other mistake: When the head counterfeiter comes in, there is a sign on the barracks behind him that says "BARRACK 3." Two problems with this. First, Hogan and company are housed in Barrack 3. Second, there is not a Barrack building between Hogan's building and Klink's office building.
Nights in Shining Armor - S3-E8
Other mistake: In the end, Schultz tests the faucets, and they work correctly. When Klink goes to touch the faucets, watch the drain. The high pressure jet of water comes from it just when Klink is over it.
Sergeant Schultz Meets Mata Hari - S3-E4
Other mistake: As the lady Gestapo spy comes into the beer hall, Schultz not only has a matchbook in hand, but keeps looking at the action between the bartender and the lady, waiting for his entrance cue.
Answer: Nimrod's actual identity was never revealed in the series. It was only known that he was a British intelligence agent. Nimrod was not Colonel Klink. Hogan had only implied it was him as a ruse to get Klink returned as camp commandant, not wanting him replaced by someone more competent who would impede the Heroes war activities. The term "nimrod" is also slang for a nerdy, doofus type of person, though it's unclear why that was his code name.
raywest ★
"Nimrod" is originally a king and hero mentioned in the Tanach and taken into the Bible and the Koran. His name is often used in the sense of "stalker," "hunter," and sometimes figuratively as "womanizer" as in "hunter of women." I've never seen it used to denote a nerdy person, and although I cannot disprove that connotation, I think given his role, the traditional meaning is more likely the intended one.
Doc ★
It's widespread enough that Wikipedia has an entire section on it: https://en.wikipedia.org/wiki/Nimrod#In_popular_culture