Division 4.2

It must be possible, from the characteristics of the traces, their relative positions and if necessary the signs laid down in Article 15 of the Regulation to distinguish clearly between the various periods of time.

The various periods of time should be differentiated from one another on the record by differences in the thickness of the relevant traces, or by any other system of at least equal effectiveness from the point of view of legibility and ease of interpretation of the record.