The augmented Backus–Naur form (ABNF) extends the
Backus-Naur form. The augmented Backus–Naur form (ABNF) is based on
Backus–Naur form (BNF), but consists of its own syntax and derivation rules. The motive principle for this
metalanguage is to describe a formal system of a language which is a
protocol (bidirectional specification). It is documented in RFC 4234 and often serves as the definition language for
IETF communication
protocol.
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ASSOCIATION OF BLACK NURSING FACULTY IN HIGHER EDUCATION. ABNF