Increasingly, documentation for computer systems and products addresses diverse audiences, ranging from professional computer engineers to novice readers who have never used a computer. This diversity presents a challenge to the computer documentation professional: how to address the needs of both novice and sophisticated users? Effective user documentation must be procedure-oriented: how to combine this goal with the fact that different user audiences have different goals and face different problems? A discussion is presented of the challenge of audience diversity in computer documentation. Using case studies (i.e. an accounting product, a database management system, and a decision support system), it reviews and recommends different ways to meet the needs of various audiences.