Police tautology

What do they sign-write on the unmarked squad cars?  "Strand undercover policing"

Anyone who can see the car does not need to be told it is "visible".

Dean Finnie, being a local, had quite a different take on it. "I was amused by the thought that the local police have to differentiate between the usual standard of invisible policing and this presumably 'premium' service of visible policing. It was the first time we'd seen the visible service!"