Footnoted in: Stanley Gibbons, not given unique numbers by Gibbons Concise 2022
½p - 16p in steps of ½p issued on 1984-05-01.
16½p and 17p issued on 1984-08-28. An experimental out of hours service available in only four locations; Cambridge, London, Southhampton and Windsor. Ended 30 April 1985.
