The article contains a characterization of some sociosemiotic rules that regulate the choice and arrangement of language units in the process of speech generation. Arguments are offered in favour of the view that the rules should be included into the generative model of an utterance. A dependency is ascertained between the constituent parts of a communicative register (a category closely related to that of speech genre) and the word selection rules of speech generation. The sociosemiotic rules of choosing a name for the agent serve as an example.