12. The Documentary Evidence Act 1868, as amended by the Documentary Evidence Act 1882, shall apply to the chief executive member of the Northern Ireland Executive as if he were mentioned in column 1 of the Schedule to the first-mentioned Act, and as if he or any person authorised by him to act on his behalf were mentioned in column 2 of that Schedule, and as if the regulations referred to in that Act included any document issued by the chief executive member.