Continuity mistake: After Shultz has been discredited, Klink is taking away the "badges of rank". When Klink goes to crush the monocle Shultz was wearing, he has his monocle on. After the shot cuts to a closeup of Shultz's monocle being crushed, and widens out, you see Klink's monocle is suddenly gone. It remains missing until Klink goes to the hat rack. The shot cuts from Klink, to Hogan and Shultz, then back, and the famous monocle is suddenly back, both without Klink stopping to take it off, or put it back on.
Continuity mistake: Notice the jacket that Carter always wears. It always appears worn with age and use. This episode, it appears almost new.
Other mistake: As Schultz talks to Burkhalter, it sounds like he says Captain.
Visible crew/equipment: As Schultz calls for attention, the studio lighting is reflected in his monocle.
Visible crew/equipment: As Schultz looks at the prisoners after being told of the escape, the studio lighting rig is reflected on his monocle.
Continuity mistake: As Schultz is addressing the formation after taking command, his swagger stick switches from his right hand to under his left arm after the camera angle changes. Also, a minute later, Carter goes from being beside Newkirk to being in front of him and back again in a few seconds.
Revealing mistake: As the scene opens, the camera starts on a shot of the guard tower's roof. As it pans left and down into the yard, over the hill on the left side of the shot you can see a modern crane structure and the corner of a building in the distance.
Continuity mistake: After Burkhalter relieves Shultz of command, and Klink is reinstated, Klink sits behind the desk. On the blotter is a letter opener that Burkhalter was toying with, and a black covered notebook. After sitting, Klink reaches in his jacket pocket, pulls out the same notebook, and reads from it. The shot cuts to Shultz and back, and the book Klink read from is gone, (presumably back in the pocket) and the one on the desk is gone.
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