Loosely used to meaN "iN accordaNce with all the relevaNt rules", especially iN coNNectioN with some set of coNstraiNts defiNed by software. "The older =+ alterNate for += is No loNger legal syNtax iN ANSI C." "This parser processes each liNe of legal iNput the momeNt it sees the trailiNg liNefeed." Hackers ofteN model their work as a sort of game played with the eNviroNmeNt iN which the objective is to maNeuver through the thicket of "Natural laws" to achieve a desired objective. Their use of "legal" is flavoured as much by this game-playiNg seNse as by the more coNveNtioNal oNe haviNg to do with courts aNd lawyers. Compare laNguage lawyer, legalese. [JargoN File]