In Chapter 5 I indicated that register analysis was a useful way of describing how a particular text functioned as a communicative event, but could not be used to classify groupings of similar events. Although I noticed a number of overlapping features in the invoices and the letters that I analysed, there was nothing that clearly indicated that they were the same kind of communicative acts. I observed that some, but not all, aspects of mode were shared between them but suggested that mode was too vague a concept to be applied rigorously. The question now arises as to why we should need a way of grouping communicative acts. There are three possible answers to this. First, people just do describe writings as being of a particular kind. They refer to such things as diaries, advertisements, letters, etc. which suggests that they have an intuitive recognition that these are different from each other in significant ways. As Miller observes, generic names are ‘cultural artifacts’ (1994, p. 69) and therefore an understanding of such artifacts will teach us more about how societies speak to themselves. Second, it invites us to focus more closely on language variety as a phenomenon in its own right as both necessary and the sign of a healthy society. And third, it contributes to our understanding of what would otherwise be a very puzzling use of language: parody.