Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: Klink was sitting in his chair as Hogan is guessing his age. Klink's hands are clasped in front of him, and a second later, his right hand is on his hip.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: When Hogan and company pull up to the ammo dump, the guard is standing to the left of the "HOCHE SPRENGGEFAHR" (high explosives) sign. A second later he is standing in front of the other end of the sign.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: As Newkirk leaves the stage to do his "hat trick", his sweater is clean. When doing the trick, there are stains on the sweater before he starts.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: When the German officer throws the dummy grenade, it lands about 15 or so feet from Hogan. In the next shot, Hogan takes only a step or two (about three or four feet) and picks it up.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: As Klink tells Hogan of his suspicion, his arms are folded. A second later, his left fist is by his mouth.
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