1856 vi. 15 Upon a book thus re-directed to any other postal district in the United Kingdom,..an additional postage is levied of one penny.
1966 J. J. Fuld Introd. 14 London was divided into postal districts (e.g., W.C.) in 1856... Postal districts in Berlin (e.g., Berlin C) were first established on Sept. 1, 1873.