The Rich Text Format (often abbreviated RTF) is a proprietary document file format with published specification developed by Microsoft Corporation since 1987 for Microsoft products and for cross-platform document interchange.
Most word processors are able to read and write some versions of RTF. There are several different revisions of RTF specification and portability of files will depend on what version of RTF is being used. RTF specifications are changed and published with major Microsoft Word and Office versions.
It should not be confused with enriched text (mimetype “text/enriched” of RFC 1896) or its predecessor Rich Text (mimetype “text/richtext” of RFC 1341 and 1521); nor with IBM’s RFT-DCA (Revisable Format Text-Document Content Architecture) which are completely different specifications.
A standard RTF file can consist of only 7-bit ASCII characters, but can encode characters beyond ASCII by escape sequences. The character escapes are of two types: code page escapes and, starting with RTF 1.5, Unicode escapes. In a code page escape, two hexadecimal digits following a backslash and typewriter apostrophe are used for denoting a character taken from a Windows code page. For example, if the code page is set to Windows-1256, the sequence \’c8 will encode the Arabic letter bāʼ (ب).
Unlike many word processing formats, concise RTF code can be made human-readable. When an RTF file is viewed as a plain text file, characters within ASCII are legible and the markup language (formatting) elements not too distracting or counter-intuitive. However, the RTF files produced by most programs, such as Microsoft Word (MS Word), will contain such a large number of control codes that most files will easily be an order of magnitude larger than the corresponding plain text and very difficult to read. Formats such as MS Word’s .doc are, in contrast, binary formats with only a few scraps of legible text.