21 Distinctive signs for hackney carriages.E+W+S
On every mechanically propelled vehicle which is chargeable with duty as a hackney carriage there shall, subject to the prescribed exceptions, be exhibited, in conjunction with the mark required under section 19 of this Act to be fixed on the vehicle, a distinctive sign indicating—
(a)that the vehicle is a hackney carriage; and
(b)the number of persons for which the vehicle has seating capacity;
and regulations under this Act shall provide for such signs to be exhibited as aforesaid.