official someone who administers the rules of a game or sport; "the golfer asked for an official who could give him a ruling"
official document law a document that states some contractual relationship or grants some right
official emissary a member of a legation
official immunity personal immunity accorded to a public official from liability to anyone injured by actions that are the consequence of exercing official authority
Official Production System Official Production System OPS The first production system i.e. rule based programming language, developed at CMU in 1970 and used for building expert systems. OPS was originally written in Franz Lisp and later ported to other LISP dialects.