.DOC

Introduction

This is the format of Word 97, 2000, 2002 and 2003, and of most .doc files in circulation. Word 2007 and later still open and save it as “Word 97–2003 Document”. It added Unicode text to the Word 6.0 and 95 design and moved the document’s tables into a stream of their own.

Microsoft publishes the format in full as [MS-DOC], one of its Office open specifications.

Structure

The file is a compound file, which starts with the signature D0 CF 11 E0 A1 B1 1A E1 and holds named streams like files in a small file system. The WordDocument stream begins with the File Information Block (FIB), whose wIdent is 0xA5EC and nFib is 193 (0x00C1), followed by the text. A flag in the FIB says whether the table stream is named 0Table or 1Table; it holds the piece table, which says where each run of text is and whether it is 8-bit or UTF-16, together with the styles, fonts, lists and formatting. Pictures live in the Data stream and embedded objects in ObjectPool.

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