4(1)In any authorised premises the holder of the occasional permission or any agent of his shall not—
(a)knowingly sell intoxicating liquor to a person under eighteen, or
(b)knowingly allow a person under eighteen to consume intoxicating liquor in a bar,
and in those premises the holder of the permission shall not knowingly allow any person to sell intoxicating liquor to a person under eighteen.
(2)A person under eighteen shall not in any authorised premises buy or attempt to buy intoxicating liquor, nor consume intoxicating liquor in a bar.
(3)No person shall buy or attempt to buy intoxicating liquor for consumption in a bar in any authorised premises by a person under eighteen.
(4)Sub-paragraphs (1) and (2) above do not prohibit the sale to or purchase by a person who has attained the age of sixteen of beer, porter, cider or perry for consumption at a meal in a part of the premises which is set apart for the service of meals and is not a bar.
(5)Any person who contravenes any provision of this paragraph shall be guilty of an offence.
(6)Where, as regards any authorised premises, the holder of the occasional permission is charged with an offence under sub-paragraph (1) above in a case in which it is proved or admitted that he did not personally have the knowledge required for the commission of the offence charged, he shall not be convicted of the offence on the basis of another's knowledge if he proves that he exercised all due diligence to avoid the commission of an offence under that sub-paragraph.
(7)References in sub-paragraphs (1) to (3) above to a bar do not include a bar at any time when it is—
(a)set apart for the service of table meals ; and
(b)not used for the sale or supply of intoxicating liquor other wise than to persons having table meals there and for consumption by such persons as ancillary to their meals.