Grice coined the term ‘conventional implicature’ in a short passage in ‘Logic and conversation’. The description is intuitive and deeply intriguing. The range of phenomena that have since been assigned this label is large and diverse. I survey the central factual motivation, arguing that it is loosely uni- fied by the idea that conventional implicatures contribute a separate dimen- sion of meaning. I provide tests for distinguishing conventional implicatures from other kinds of meaning, and I briefly explore ways in which (...) one can incorporate multiple dimensions of meaning into a single theory. (shrink)