This International Standard describes methods of scribing coated steel or test-pieces for corrosion tests, where the coating system is applied at dry film thicknesses of less than 500 μm. It is intended as a guideline only, being based on the results of a collaborative trial with no subsequent corrosion testing having been carried out to determine the suitability of the introduced scribe marks for such tests. This International Standard covers the scribing of metallic panels or test pieces made from — steel, — chemically treated steel, — aluminium or aluminium alloy, and — chemically treated aluminium. It does not cover the scribing of galvanized or electroplated metal or clad aluminium panels.