Non-referential indices or "pure" indices do not contribute to the semantico-referential value of a speech event yet "signal some particular value of one or more contextual variables." Non-referential indices encode certain metapragmatic elements of a speech event's context through linguistic variations. The degree of variation in non-referential indices is considerable and serves to infuse the speech event with, at times, multiple levels of pragmatic "meaning." Of particular note are: sex/gender indices, deference indices (including the affinal taboo index), affect indices, as well as the phenomena of phonological hypercorrection and social identity indexicality.