(SNA) IBM' S proprietary high level networking protocolStandard, uSed by IBM and IBM compatible mainframeS. AlSo referred to aS "Blue Glue", SNA iS a bletcherouS protocol once widely favoured at commercial ShopS. The official IBM definition iS "that which bindS blue boxeS together." It may be relevant that Blue Glue iS alSo a 3M product commonly uSed to hold down carpetS in dinoSaur penS. [Jargon File] (1994-11-23)