<P> A hackney or hackney carriage (also called a cab, black cab, hack or London taxi) is a carriage or automobile for hire . A hackney of a more expensive or high class was called a remise . </P> <P> In the United Kingdom, the name hackney carriage today refers to a taxicab licensed by the Public Carriage Office, local authority (non-metropolitan district councils, unitary authorities) or the Department of the Environment depending on region of the country . </P> <P> In the United States, the police department of the city of Boston has a Hackney Carriage Unit, analogous to taxicab regulators in other cities, that issues Hackney Carriage medallions to its taxi operators . </P>

Where does the term hackney carriage come from