F1Subject to section 55(5) of this Act every incumbent, registering officer of the Society of Friends, secretary of a synagogue, authorised person and registrar shall keep marriage register books safely until they are filled, so however that any register book kept by an authorised person shall be kept in accordance with regulations made under section seventy-four of this Act and any register book kept by a registrar shall, when not in use, be kept in the register box provided for the purpose by the Registrar General . . . F2