HD 22 applies to rigid and flexible cables, sheathed and unsheathed, and insulated with cross-linked material, of rated voltages Uo/U up to and including 450/750V, used in power installations. This Part 1 specifies the general requirements applicable to these cables. The test methods specified are given in Part 2 of this Harmonization Document (HD), or in the common test methods for cables given in EN 50265, EN 50266, EN 50267, EN 50268 and EN 60811. The particular types of cables are specified in Part 3 onwards of this HD, which are hereafter referred to as "the particular specifications". The code designations of these types of cables are in accordance with HD 361.