Green’s Dictionary of Slang

(UK und.) defrauding parish officers by using forged Admiralty and War Office passes, thus router, one who purses this form of fraud.

1825

Pierce Egan’s Life in London 27 Mar. 70/2: [T]he system itself is technically called routing—probably because in every War Office pass the route of the person hearing it is laid down. The head-quarters of the routers are in St. Giles's parish [in London].