You got it! Darn Google!

It was from a ST:TNG episode ("Relics") where Scotty (Chief Engineer from TOS) made a cameo. He had been stuck in a transporter feedback loop (don't ask) and was rescued by the TNG crew. As they showed him around the Enterprise NCC-1701D, he was getting lonesome for the Enterprise of yore, noting that the TOS Enterprise was "NCC One Seven Oh One, no bloody, A, B, C or D".
Seemed an appropriate quote for the thread.