57.—(1) This regulation applies in relation to a licence under regulation 55 or 56.
(2) A licence—
(a)may be, to any degree, general or specific;
(b)except where regulation 55(6) applies, may be granted either to persons of a class or to a particular person; and
(c)may be subject to compliance with any specified conditions.
(3) For the purposes of a licence the definition of a class of persons may be framed by reference to any circumstances whatever including, in particular, their being authorised by any other person.
(4) A licence may be modified or revoked at any time by the authority which granted it, but is otherwise valid for the period stated in the licence.
(5) The relevant licensing body may charge for a licence such reasonable sum (if any) as it may determine.