The guiding idea of this collection is to bring together a number of different perspectives on variation in language according to occasion of use. At present this is a rather ill-defined field of interest sometimes referred to as style variation and sometimes as register variation. This area has not figured as prominently in sociolinguistics as certain and other aspects of variation (social dialect variation in particular). This volume draws attention to the importance of this ubiquitous linguistic phenomenon and points the way to a unified approach. Biber and Finegan have solicited studies presenting a variety of perspectives on registers and register variation, as well as papers that attempt to integrate register and social dialect variation into a coherent theoretical framework.