It is to be recognized that numerous test methods are specific to particular optical fibre submarine cable system designs and are, therefore, proprietary information of the system designer/supplier. However, a common understanding needs to be met between the system designer/supplier and the system purchaser/operator about the general purpose of testing and the meaning of the results. Recommendation ITU-T G.976 highlights the purpose of testing in optical fibre submarine cable systems and to list the main test methods applicable to these systems. Specific test methods are described. This edition of this Recommendation includes the addition of test regarding vibration and shock resistance.