At least 50% of all tiles and 10% of accessories supplied must include an indelible and legible marking, either coded or not, that identifies the maker and the production unit, as well as the country of origin, the year and the month of production.

All documents supplied must refer to norm NP EN 1304, specify the impermeability class and the testing method used to evaluate this requisite, as well as the testing method to evaluate frost resistance (A, B, C or D).