if S.startswith("[") and not S.startswith("[FD."):
            if not S.startswith("[FV.") and not S.startswith("[CAPSULE.") \
                and not S.startswith("[VTF.") and not S.startswith("[RULE."):
                raise Warning("Unknown section At Line ", self.FileName, self.CurrentLineNumber)
            self.__UndoToken()