You must have been wondering—haven’t we all?—what happened to Mr. P.C.’s Guide To Jazz Etiquette And Bandstand Decorum. The jazz world’s indispensible source of advice has become harder to find, but not impossible. His latest installment has to do with CDs, their ubiquity or the lack of it, and how to properly dispose of one if it should happen to inadvertently make its way into your horn case or backpack. To read the column, go here, and make note of the web address for future reference.