The programme schedules provided by the Welsh Authority under section 47(1)(b) shall include periods available for the broadcasting of advertisements; and it shall be the duty of the Welsh Authority to provide those programme schedules far enough in advance to enable the IBA to operate the arrangements required by section 13(3)(a).

In any programme schedule so provided, no period available for the broadcasting of advertisements shall be located in any break in or, without the consent of the BBC, at the beginning or end of any programme supplied or to be supplied to the Welsh Authority by the BBC.