In addition, carcases or half-carcases may be bought in only where they are: ... identified, first, by markings indicating the category, the conformation class and the degree of fat cover and, secondly by an identification or slaughter number. Markings indicating the category, conformation class and fat cover must be perfectly legible and shall be stamped with non-toxic, fast, indelible ink using a procedure approved by the competent national authorities; the letters and figures must be at least 2 cm high.