介绍了符合ISO 8879的四种文件类型定义和附加设施。旨在为书籍、文章和系列出版物的创建和交换提供文档体系结构。指定定义文档类型定义和文档实例使用的语法的SGML声明；文档类书籍、文章、期刊的文档类型定义；数学文档类型定义，可嵌入其他SGML应用程序中。

Presents four document type definitions and additional facilities conforming to ISO 8879. Intended to provide document architectures for the creation and interchange of books, articles and serial publications. Specifies the SGML declaration defining the syntax used by the document type definitions and document instances; the document type definitions for the document classes books, articles, serials; a document type definition for Mathematics which may be embedded in other SGML applications.