rule of evidence (law) a rule of law whereby any alleged matter of fact that is submitted for investigation at a judicial trial is established or disproved
miranda rule the rule that police (when interrogating you after an arrest) are obliged to warn you that anything you say may be used as evidence and to read you your constitutional rights (the right to a lawyer and the right to remain silent until advised by a lawyer)
precept,
principle a basic truth or law or assumption; "the principles of democracy"
golden rule a command based on Jesus' words in the Sermon on the Mount; "Whatsoever ye would that men do unto you, do you even so unto them" (Matthew 7:12)
gigo (computer science) a rule stating that the quality of the output is a function of the quality of the input; put garbage in and you get garbage out
dictate a guiding principle; "the dictates of reason"