A memorandum (pl.: memorandums or memoranda; from the Latin memorandum, "(that) which is to be remembered"), also known as a briefing note, is a written
concern a particular officer or office of the Government." Memorandum circulars (Filipino: Memorandum sirkular), according to Book III, Title I, Chapter II
recognized under MemorandumOrder 427, issued by then President Ferdinand Marcos, confirming the existence of the Sultanate of Sulu. MemorandumOrder No. 427 states