Klink for the Defense - S6-E19
Visible crew/equipment: As Newkirk and Hogan enter the office, the shadow of the boom mic plays on the wall.
Visible crew/equipment: As Schultz calls for attention, the studio lighting is reflected in his monocle.
Visible crew/equipment: As Schultz drives away from the boys, the camera crew and equipment is reflected in the window.
Visible crew/equipment: As Schultz looks at the prisoners after being told of the escape, the studio lighting rig is reflected on his monocle.
Visible crew/equipment: As the man gets in the passenger side of the car after the agreement is signed, the studio lighting rig is reflected in the glass.
Visible crew/equipment: When Major Hochstetter's car arrives at Stalag 13, it drives towards the camera. The shadow of a crewman's hand raised to stop the car is visible on the ground. (00:16:40)
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