﻿DIGIT     = "0" / "1" / "2" / "3" / "4"  ; DIGIT is a core ABNF rule
          / "5" / "6" / "7" / "8" / "9"

SIGN      = "+" / "-"                    ; "+" or "-"

INTEGER   = [ SIGN ] 1*DIGIT             ; An optional sign, followed by 1 or more digits