An instrument that serves notice of decision taken by the executive arm of government. For example, an Order in Council accompanies all regulations. The OIC says "we've decided to put these regs into force" and presents the regs.
A legal instrument made by the Governor in Council pursuant to a statutory authority or, less frequently, the royal prerogative. All orders in council are made on the recommendation of the responsible Minister of the Crown and take legal effect only when signed by the Governor General.
an instrument used to exercise power that the Legislative Assembly has delegated to Cabinet, most often a single Minister