Article 31
(1) A guarantee mark is a sign that serves for guaranteeing the common characteristics of the undertakings, production methods, geographical origin and quality of those undertakings, under the control of the proprietor of the mark.
(2) The use of a guarantee mark for goods or services of the trademark proprietor or undertakings economically linked to proprietor is prohibited.
(3) Collective mark is a sign used by a group of undertakings of producers or traders or providers of services.
(4) Collective mark serves the purpose of distinguishing the goods and services of the undertakings from those of other undertakings.