Green’s Dictionary of Slang

1. a playing card.

1969		S.T. Kendall Up the Frog.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
1992		R. Puxley Cockney Rabbit.

2. a card as used in the game of bingo.

1960		J. Franklyn Dict. of Rhy. Sl.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.

3. Scotland Yard, former headquarters of the Metropolitan Police.

1959		J. Gosling Ghost Squad 25: Thieves’ argot, spoken properly, is a foreign language which needs to be learned [...] ‘bogies’ or ‘jockeys’ are policemen and ‘bladder’ (bladder of lard) means New Scotland Yard.
1992		R. Puxley Cockney Rabbit.