abnf.txt

# configuration = or-sequence 
#
# or-sequence  = and-sequence *(1*CRLF (otherwise-directive / and-sequence)
# and-sequence = *(directive CRLF)
#
# directive = ["NOT"] predicate / action / group-directive / or-directive
# group-directive = "{" or-sequence "}"
# 
# predicate =  <header> ":" <value>
#           / "$" <json-path> ":" <value>
#
# action = "DROP"
#        / "DRY"
#        / "EXIT"
#        / "LOG" <macro-string> ["&&"]; double ampersand in macro-string must be escaped
#        / "POST" <macro-string>; must expand to an absolute-URI
#        / "FOR" <variable> "IN" "$" <json-path> <group-directive>
#        / "REENTER [COPY]"
#        / "SET" <header> ":" <macro-string>
#
#
# or-directive        = "or" "{" 1*(directive CRLF) "}"
# otherwise-directive = "otherwise" directive
#
# macro-string     = *( macro-expand / macro-literal / macro-escape)
# macro-expand     = ( "${" macro-expansion "}" )
# macro-escape     = "\\" / "\#" / "\$" / "\&"
# macro-literal    = %x20-22 / %x25-5B / %x5D-7E; space and visible characters except "#", "$", "\"
# macro-expansion  = 1*(ALPHA / DIGIT / "-" / "_" / ".")