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Status:

INTERNET STANDARD

Obsoletes:

RFC 4234

Updated by:

RFC 7405

Authors:

D. Crocker, Ed.
P. Overell

Stream:

IETF

Source:

NON WORKING GROUP

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DOI:  https://doi.org/10.17487/RFC5234

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Abstract

Internet technical specifications often need to define a formalsyntax. Over the years, a modified version of Backus-Naur Form(BNF), called Augmented BNF (ABNF), has been popular among manyInternet specifications. The current specification documents ABNF.It balances compactness and simplicity with reasonablerepresentational power. The differences between standard BNF andABNF involve naming rules, repetition, alternatives,order-independence, and value ranges. This specification alsosupplies additional rule definitions and encoding for a core lexicalanalyzer of the type common to several Internet specifications. [STANDARDS-TRACK]

For the definition ofStatus,seeRFC 2026.

For the definition ofStream, seeRFC 8729.