The SGML FAQ Book: Understanding the Foundation of HTML and XML is similar, but not quite the same kind of thing as an online FAQ or `Frequently Asked Questions' list. It addresses questions from people who already actually use SGML in some way (including HTML authors), and people who are about to use it. It deals mainly with issues that arise when using SGML in practice. A very brief introduction to SGML is included as Appendix A. The questions discussed in The SGML FAQ Book are repeatedly heard by people who make their living serving the SGML community. SGML experts spend many hours teaching these details, sometimes repeatedly because some questions do not seem important -- until you run into them. So one benefit of this book is learning more of the art of document creation and management, both by general reading before questions arise and by specific reference when a question arises. For the latter use, the appendices, glossary, and index are particularly important. A second benefit of this book is that it provides a common theme to its answers that you can apply in your use of SGML, HTML and related languages in general. The fundamental answer to many of the questions boils down to `simplify': many questions do not show up if you use the simple, elegant core of SGML without worrying about optional features. The credo of this book is simply, `SGML doesn't need to be complicated'. SGML has the potential for complexity at certain points. But much of the complexity comes from optional parts and can be avoided. SGML methodology and its primary benefits suffer no loss even if you skip many features, which speaks well for the quality of SGML's overall design. Many of the questions discussed involve those optional parts, and therefore can be avoided by judicious designers and authors. The two key goals of the book are (1) to answer questions that you may actually encounter as an SGML user, and to help you get `unstuck' and be as productive as possible in using the language and (2) to show proactive ways you can simplify your use of SGML, and get its very substantial benefits with minimal complexity.