5.8.8.3. After verification of the general specifications (paragraph 4.) and the specifications of shape and dimensions (Annex 5) four samples shall be subjected to the heat resistance test described in Annex 6, prior to the tests described in paragraphs 4.2. and 5.7.4. and in Annex 8. The fifth sample shall be kept for reference purposes during the test procedures. a0c0