in law, a memorandum opinion is usually an unpublished legal opinion that cannot be cited as precedent. it is formally defined as: "[1] unanimous appellate opinion that succinctly states the decision of the court; an opinion that briefly reports the court's conclusion, usu. without elaboration because the decision follows a well-established legal principle or does not relate to any point of law." there is no elaboration or explanation because the decision either follows a well-known legal principle or it does not relate to a point of law. a memorandum opinion is also not subject to appeal.