Proper noun
the R-principle
In the neo-Gricean semantics and pragmatics of Laurence R. Horn: a reformulation of Paul Grice's maxim of relation combined with the second submaxim of quantity and the third and fourth submaxims of manner, stating: "Say no more than you must (given Q)", and implying that there is no reason to make a stronger statement if the extra information can be contributed by implicature.
Coordinate term: Q-principle