Article 28

1.   Member States may provide for the registration of guarantee or certification marks.

2.   Any natural or legal person, including institutions, authorities and bodies governed by public law, may apply for guarantee or certification marks provided that such person does not carry on a business involving the supply of goods or services of the kind certified.
Member States may provide that a guarantee or certification mark is not to be registered unless the applicant is competent to certify the goods or services for which the mark is to be registered.

3.   Member States may provide that guarantee or certification marks are not to be registered, or are to be revoked or declared invalid, on grounds other than those specified in Articles 4, 19 and 20, where the function of those marks so requires.

4.   By way of derogation from Article 4(1)(c), Member States may provide that signs or indications which may serve, in trade, to designate the geographical origin of the goods or services may constitute guarantee or certification marks. Such a guarantee or certification mark shall not entitle the proprietor to prohibit a third party from using in the course of trade such signs or indications, provided that third party uses them in accordance with honest practices in industrial or commercial matters. In particular, such a mark may not be invoked against a third party who is entitled to use a geographical name.

5.   The requirements laid down in Article 16 shall be satisfied where genuine use of a guarantee or certification mark in accordance with Article 16 is made by any person who has the authority to use it.