[F1 [F2Article 17a U.K.
Austria and Finland shall have a period of three years from the date of entry into force of theAccession Treaty to introduce the checking system provided for in this Chapter. During that transitional period, Austria and Finland shall apply the measures which will be determined before the date of entry into force of the Accession Treaty in accordance with the procedure laid down in Article 23. These measures must ensure that all the necessary checks are carried out as close as possible to the Community's external frontier.] ]