*.abnf
;
([a-zA-Z][a-zA-Z0-9-]*|<[a-zA-Z][a-zA-Z0-9-]*>)
(\%{rulename})
%b[0-1]+(\-[0-1]+|(\.[0-1]+)*)
%d[0-9]+(\-[0-9]+|(\.[0-9]+)*)
%x[0-9a-fA-F]+(\-[0-9a-fA-F]+|(\.[0-9a-fA-F]+)*)
"[ !#$%&'\(\)\*\+,\-\./0-9:;<=>\?@A-Z\[\\\]\^_`a-z\{\|\}~]*"
^\s*(\%{rulename})\s*=/?
^(?!\s)