Quora has the answer already? Even Stackoverflow-http://stackoverflow.com/questions/184618/what-is-the-best-c...

//when I wrote it only GOD and I knew what it does. Now only GOD knows.

It was a self-commenting C++ friend function named "ifyouusethisfunctioniwillstrangleyoumyself", written by our extremely talented team leader. There were a couple of times it was necessary to call this function; the name was there merely to make people think about whether they REALLY needed to call it. Discovering the function itself meant people had already identified some need in their code for it. So - no actual comment, but a very wonderful piece of code that make people think, and prompted many discussions about the correctness of what they were attempting.

Customer(The.Bastard)

Found in GoldMine code in 2000 beta testing. Changed shortly after.

EDIT: Not actually a comment, it was a variable named Customer with a property (The.Bastard).