diff --git a/symbol.go b/symbol.go
index e9983b3..308bde1 100644
--- a/symbol.go
+++ b/symbol.go
@@ -71,6 +71,7 @@ const (
 	SymComment
 	SymFunction
 	SymList
+	SymKwBut
 	// SymOpenComment                       //   0: '/*'
 	// SymClosedComment                     //   0: '*/'
 	// SymOneLineComment                    //   0: '//'
@@ -82,7 +83,8 @@ func init() {
 	//keywords = make(map[string]Symbol)
 	keywords = map[string]Symbol{
 		"AND": SymKwAnd,
-		"OR":  SymKwOr,
+		"BUT": SymKwBut,
 		"NOT": SymKwNot,
+		"OR":  SymKwOr,
 	}
 }