Doug told me a joke once after I used that term. This doesn't answer your question, but here it is (retold from memory, hope I get it right):

A businessman travels to Boston, and hails a taxi at the airport. He's in the mood for some seafood, so he asks the cab driver, "Hey, do you know where I can get scrod around here?"

The driver replies, "Buddy, I've been asked that question a million times in a million different ways. But that's the first time I've ever heard it said in the pluperfect subjunctive."