(1) The holder of an authority must immediately produce the authority for
inspection on demand by--
(a) any person with whom the holder has contracted
to do residential building work or specialist work or to whom the holder has
made a statement indicating that the holder is willing or prepared to do any
such work or to enter into a contract to do any such work, or
(b) the owner
or occupier of any land, building, vehicle or vessel on or in which the holder
is doing residential building work or specialist work or on or in which the
holder has contracted to do any such work, or
(c) any person authorised in
writing for the purposes of this section by the Secretary, or
(d) any person
authorised in writing for the purposes of this section by any local or public
authority which is responsible for the control of residential building work or
specialist work which the holder is carrying out, or