(linguistics, phonology, Indo-European studies) A rule of the Proto-Indo-European reconstructed language that states that a labiovelar stop (*kʷ, *gʷ, *gʷʰ) dissimilates to an ordinary velar stop (*k, *g, *gʰ) next to the vowel *u or its corresponding glide *w.

(UK, politics) A constitutional convention (which acquired legal force in 2010) dictating that most international treaties had to be laid before Parliament 21 days before ratification.

plural of prophylactic rule

(law) A judge-made rule that overprotects a constitutional right in order to safeguard that right or facilitate detection of violations of it.

(cellular automata) A one-dimensional binary cellular automaton rule, notable for solving the majority problem as well as for its ability to simultaneously describe several, seemingly quite different, particle systems.

(cellular automata) A one-dimensional binary cellular automaton rule displaying aperiodic, chaotic behaviour.

(cellular automata) An elementary cellular automaton based on the exclusive-or function.

(law) The common-law rule according to which the unexpected frailty of an injured person is not a valid defense to the seriousness of any injury caused to them.

(law) Synonym of fireman's rule

(law) A common law rule according to which an ambiguous criminal law should be interpreted in the way most favorable to the defendant.