Found on Wikipedia, no. 1
“David Simon has said that, when working on the book Homicide: A Year on the Killing Streets, Jay Landsman and he discussed the possibility that homicide detectives would be able to communicate solely through the word “fuck”. Years later, in this episode, he fulfilled this fantasy by having Bunk and McNulty successfully work a crime scene, communicating only through that word.” (link)
One of the classic scenes of American television (watch it here).