updated comments

parser.go

@@ -33,7 +33,7 @@ const (
 	Unspecified SpfErrorKind = "unspecified"
 )
 
-// SpfError represents parsing error, it holds reference to faulty token
+// SpfError represents errors created from parsing or validation, it holds reference to faulty token
 // as well as error describing fault
 type SpfError struct {
 	kind  SpfErrorKind