Editing Extended Backus–Naur form (section)

==Advantages over BNF==
Any [[grammar]] defined in EBNF can also be represented in BNF, though representations in the latter are generally lengthier. E.g., options and repetitions cannot be directly expressed in BNF and require the use of an intermediate rule or alternative production defined to be either nothing or the optional production for option, or either the repeated production of itself, recursively, for repetition. The same constructs can still be used in EBNF.

The BNF uses the symbols (<code>&lt;</code>, <code>&gt;</code>, <code>|</code>, <code>::=</code>) for itself, but does not include quotes around terminal strings. This prevents these characters from being used in the languages, and requires a special symbol for the empty string. In EBNF, [[Terminal symbol|terminals]] are strictly enclosed within quotation marks (<code>"</code>...<code>"</code> or <code>'</code>...<code>'</code>). The angle brackets (<code>&lt;</code>...<code>&gt;</code>) for [[Terminal and nonterminal symbols|nonterminals]] can be omitted.

BNF syntax can only represent a rule in one line, whereas in EBNF a terminating character, the semicolon character <code>;</code> marks the end of a rule.

Furthermore, EBNF includes mechanisms for enhancements, defining the number of repetitions, excluding alternatives, comments, etc.