#ABNF 1.0 UTF-8; language en-US; mode voice; tag-format; root $Bloodtype; $letter = (/1.5/ "A B" {$ = "AB"}| /2/ "A" {$ = "A"}| "B" {$ = "B"}| "O" {$ = "O"}); $rh = (PLUS | POSITIVE):"+"| (MINUS | NEGATIVE):"-"; $type = ( TYPE ); $Bloodtype = {$=""} [$type] $letter {$+=$$} $rh {$+=$$};