Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA), March 2003
- File formats:
- PROPOSED STANDARD
- Updated by:
- RFC 5891
- A. Costello
- idn (int)
Discuss this RFC: Send questions or comments to firstname.lastname@example.org
Punycode is a simple and efficient transfer encoding syntax designed for use with Internationalized Domain Names in Applications (IDNA). It uniquely and reversibly transforms a Unicode string into an ASCII string. ASCII characters in the Unicode string are represented literally, and non-ASCII characters are represented by ASCII characters that are allowed in host name labels (letters, digits, and hyphens). This document defines a general algorithm called Bootstring that allows a string of basic code points to uniquely represent any string of code points drawn from a larger set. Punycode is an instance of Bootstring that uses particular parameter values specified by this document, appropriate for IDNA. [STANDARDS-TRACK]
For the definition of Status, see RFC 2026.
For the definition of Stream, see RFC 4844.