Book excerpt: Here's your one source for reference entries for individual elements of the SAS language in an alphabetized, encyclopedia format. This title is intended for users with previous experience with SAS or who have atleast an intermediate level of expertise with another programming language. Use this title for complete reference information for all nonoperating-environment-specific features of the SAS language. In this context, language includes all features that are not procedures. SAS Language Reference: Concepts is a companion volume to this title, providing essential concepts for SAS features, the DATA step, and SAS files. This title is available for purchase as a hardcopy book or e-book, or in the SAS OnlineDoc CD-ROM with PDF files. The HTML version of the SAS OnlineDoc CD-ROM is shipped free with Version 8.