4Unsolicited publications.
(1)A person shall be guilty of an offence if he sends or causes to be sent to another person any book, magazine or leaflet (or advertising material for any such publication) which he knows or ought reasonably to know is unsolicited and which describes or illustrates human sexual techniques.
(2)A person found guilty of an offence under this section shall be liable on summary conviction to a fine not exceeding £100 for a first offence and to a fine not exceeding £400 for any subsequent offence.
(3)A prosecution for an offence under this section shall not in England and Wales be instituted except by, or with the consent of, the Director of Public Prosecutions.