Augmented Backus-Naur Form (ABNF) Notation and Rules
ABNF Core Rules
RFC 5234 – Appendix B.1OCTET =
%x00-FF
; 8 bits of data
; 8 bits of data
CHAR =
%x01-7F
; any 7-bit US-ASCII character,
; excluding NUL
; any 7-bit US-ASCII character,
; excluding NUL
VCHAR =
%x21-7E
; visible (printing) characters
; visible (printing) characters
ALPHA =
%x41‑5A /
%x61‑7A
; A‑Z / a‑z
; A‑Z / a‑z
DIGIT =
%x30‑39
; 0-9
; 0-9
CTL =
%x00‑1F /
%x7F
; any US-ASCII control character:
; (octets 0 - 31) and DEL (127)
; any US-ASCII control character:
; (octets 0 - 31) and DEL (127)
HTAB =
%x09
; horizontal tab
; horizontal tab
LF =
%x0A
; linefeed
; linefeed
CR =
%x0D
; carriage return
; carriage return
SP =
%x20
; space
; space
DQUOTE =
%x22
; " (Double Quote)
; " (Double Quote)
BIT =
"0" /
"1"
HEXDIG =
DIGIT /
"A" /
"B" /
"C" /
"D" /
"E" /
"F"
; Note: according to the 'char-val' rule,
; letters (A-F) are case insensitive
; Note: according to the 'char-val' rule,
; letters (A-F) are case insensitive
CRLF =
WSP =
LWSP =