Editing Augmented Backus–Naur form (section)

==Overview==

[[File:ABNF syntax diagram of ABNF core rules.png|thumb|alt=ABNF syntax diagram of ABNF rules|ABNF [[syntax diagram]] of ABNF rules]]

An ABNF specification is a set of derivation rules, written as
{{sxhl|2=abnf|1=
 rule = definition; comment CR LF
}}
where rule is a [[case sensitivity|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: <code><rulename></code>, <code><Rulename></code>, <code><RULENAME></code>, and <code><rUlENamE></code> all refer to the same rule. Rule names consist of a letter followed by letters, numbers, and hyphens.

Angle brackets (<code><</code>, <code>></code>) 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.