— the presence of colourless chromate conversion coatings,

— the presence of hexavalent chromium in colourless and coloured coatings on zinc or cadmium or aluminium-zinc (mass fraction of aluminium: 55 %, within a range of 54 % to 56 % mass fraction) and zinc-aluminium (mass fraction of aluminium: 5 %) alloys,

— the total chromium content per unit area on zinc and cadmium,

— the mass per unit area of both colourless and coloured coatings,

— the satisfactory adhesion of chromate conversion coatings, and

— the quality of chromate coatings.

— colourless and coloured chromate conversion coatings containing trivalent and hexavalent chromium in varying proportions and produced by either chemical or electrochemical processes, and

— chromate coatings that are free from any supplementary coatings, such as oil, water or solvent-based polymers or wax.