In the 20th century, humorologists thought that the knew the worst kind of humor, humor so bereft of actual humor that it almost wasn't humor. They thought it was the "pun".
The 21st century has proved them wrong. There is in fact a lower form of "for lack of a better category, I guess we'll reluctantly file that under humor". It is the "reference".
Mere references, lacking any other point of interest, do not do well around here. I am comfortable with this.
The reference, once achieving a certain obscurity, elevates itself to the "inside joke" and is often used as a form of social signaling to promote in-grouping and comradery.
