{"draft":"draft-crocker-abnf-rfc2234bis-00","doc_id":"RFC4234","title":"Augmented BNF for Syntax Specifications: ABNF","authors":["D. Crocker, Ed.","P. Overell"],"format":["ASCII","HTML"],"page_count":"16","pub_status":"DRAFT STANDARD","status":"DRAFT STANDARD","source":"IETF - NON WORKING GROUP","abstract":"Internet technical specifications often need to define a formal\r\nsyntax.  Over the years, a modified version of Backus-Naur Form (BNF),\r\ncalled Augmented BNF (ABNF), has been popular among many Internet\r\nspecifications.  The current specification documents ABNF.  It\r\nbalances compactness and simplicity, with reasonable representational\r\npower.  The differences between standard BNF and ABNF involve naming\r\nrules, repetition, alternatives, order-independence, and value\r\nranges.  This specification also supplies additional rule definitions\r\nand encoding for a core lexical analyzer of the type common to\r\nseveral Internet specifications.  [STANDARDS-TRACK]","pub_date":"September 2005","keywords":["ABNF","backus-naur form","augmented backus-naur form","rule definitions","encoding","core lexical analyzer","electronic mail"],"obsoletes":["RFC2234"],"obsoleted_by":["RFC5234"],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC4234","errata_url":"https:\/\/www.rfc-editor.org\/errata\/rfc4234"}