I was listening to the Always Sunny podcast, I'm not a super fan or anything, but I do love learning how the sausage is made so to speak.

At one point they were talking about a talent agent who sat down across from one of them and after a long awkward stare says to them "...BHB."

I forget who it was but after they kept saying they had no idea what BHB means the guy lets out "...Big Heads Book"