legal

legal adj.  Loosely used to mean `in accordance with all the
   relevant rules', esp. 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 flavored as much by this game-playing sense as
   by the more conventional one having to do with courts and lawyers.
   Compare {language lawyer}, {legalese}.