Rich Text Format MIME Type

What does text/rtf mean?

text/rtf is a registered media type for Rich Text Format (RTF), Microsoft's text-based document interchange format. An RTF file combines readable text with commands for fonts, styles, paragraphs, tables, pictures, page layout, comments, and other document features.¹

The usual filename extension is .rtf. Conforming RTF data begins with the ASCII characters {\rtf, or 7B 5C 72 74 66 in hexadecimal. A version number follows the prefix, so a typical file starts with {\rtf1.²

The IANA registration for text/rtf has no required or optional parameters. It also says that RTF declares character encoding inside the document, so an external charset parameter is redundant.³

Why are there both text/rtf and application/rtf?

IANA registers both text/rtf and application/rtf for Rich Text Format. The text/rtf registration dates from June 1993 and describes the RTF variant then in use as seven-bit data with inline images. The later application/rtf registration accounts for newer RTF versions that may contain unencoded eight-bit characters and binary picture data.³⁴

For an existing .rtf file, these labels usually identify the same document family. They can still lead software down different handling paths, however. Preserve a sender's media type when compatibility matters, and use application/rtf when a recipient or protocol specifically requires the application type.

Neither label means text/richtext. That was an older MIME formatting language with angle-bracket commands, not Microsoft's brace-and-backslash syntax. Its IETF successor was renamed text/enriched partly to avoid this confusion.⁵

How RTF represents a document

Here is a small complete RTF document:

{\rtf1\ansi\deff0
{\fonttbl{\f0 Arial;}}
\f0\fs24 Plain, \b bold\b0, and \i italic\i0 text.\par
}

The outer group starts with \rtf1. The \fonttbl destination declares fonts, \fs24 selects 24 half-points, \b turns bold on, \b0 turns it off, and \par ends a paragraph. RTF readers maintain formatting state as groups nest. Readers can skip optional destinations they do not understand, which helps documents move between software supporting different RTF versions.¹

Characters outside basic ASCII may appear through code-page declarations, hexadecimal byte escapes, or Unicode control words paired with fallback text. Visible words can therefore be split by syntax. A plain-text search-and-replace can accidentally change a control word, delimiter, font table, or fallback sequence.

RTF can also embed pictures and objects. This is why its source may be much larger than the visible text and why changing a filename extension does not convert it to plain text, HTML, or a modern word-processing format.

History and current use

Microsoft described an early RTF in the March 1987 issue of Microsoft Systems Journal. RTF 1.0 followed in June 1992. The company revised the format alongside Word, ending with RTF 1.9.1 for Word 2007 in March 2008.²

RTF was designed to move formatted documents between applications and operating environments. It remains useful for relatively simple editable documents because many word processors support it. Newer Word features are not added to the format, though, and complex layout, fields, drawings, tracked changes, or embedded objects may not survive the same way in every application.²

How to open a text/rtf file

Web browsers do not normally render RTF as a formatted page. Use an application that understands the document model when appearance matters:

• Microsoft Word supports .rtf as a word-processing format.⁶
• Apple TextEdit can open, edit, save, and convert RTF documents.⁷
• LibreOffice Writer provides a Rich Text Format import and export filter.⁸

A text or code editor is useful when you want to inspect the control words. Check for the {\rtf prefix rather than trusting the .rtf suffix alone.

Support in Poly

Poly recognizes .rtf files labeled text/rtf and opens their source in the text editor. You can search both the raw text and its semantic meaning, and the Poly agent can read or edit that same source.

This is source-level support rather than formatted-document support. Poly does not lay out pages, render styles, create document thumbnails, or interpret embedded objects for text/rtf. Search results may include control words, font names, metadata, fallback characters, and other source content that would not appear as ordinary body text in a word processor.

For a dependable page preview or clean page-aware reading, convert a trusted RTF to PDF. For continued editing in a modern document format, DOCX or ODT is usually more suitable.

Converting RTF safely

Choose a destination based on the result you need:

Conversion requires an RTF-aware application. Renaming report.rtf to report.pdf or report.docx changes only the name, not the document bytes.

Security, privacy, and interoperability

The 1993 text/rtf registration calls the format safe to transmit because it provides no way to write data to a recipient's filesystem.³ Treat that as a historical statement about the format, not a guarantee about every modern parser. The newer application/rtf registration warns that RTF can reference external files and objects, and that resolving them must respect security policy.⁴

Unexpected RTF attachments deserve the same care as other complex documents. Use maintained software, avoid external content from an untrusted source, and isolate suspicious files. Embedded objects, fields, deeply nested groups, and parser flaws can create risks even though RTF itself has no general-purpose executable language.

RTF may also carry metadata in an \info group, including author, company, title, comments, and timestamps. Comments and tracked changes can retain text that is easy to miss in the final view.² Review document properties and revisions before publishing sensitive material.