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In computer science, Augmented Backus–Naur Form (ABNF) is a metalanguage based on Backus–Naur Form (BNF), but consisting of its own syntax and derivation rules. The motive principle for ABNF is to describe a formal system of a language to be used as a bidirectional communications protocol. It is defined by (''Internet Standard 68'' ) ("STD 68", type case sic), which is RFC 5234, and it often serves as the definition language for IETF communication protocols.〔 〕〔 〕 RFC 5234 supersedes RFC 4234 (which superseded RFC 2234 and RFC 733).〔 〕 RFC 7405 updates it, adding a syntax for specifying case-sensitive string literals. ==Introduction== An ABNF specification is a set of derivation rules, written as rule = definition ; comment CR LF where rule is a case-insensitive nonterminal, the definition consists of sequences of symbols that define the rule, a comment for documentation, and ending with a carriage return and line feed. Rule names are case insensitive: , , , and all refer to the same rule. Rule names consist of a letter followed by letters, numbers, and hyphens.Angle brackets (“ < ”, “> ”) are not required around rule names (as they are in BNF). However they may be used to delimit a rule name when used in prose to discern a rule name.抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Augmented Backus–Naur Form」の詳細全文を読む スポンサード リンク
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