350.52.2. Except in the prescribed cases, the operator of an establishment providing restaurant services who is a registrant shall, where the establishment is referred to in the second paragraph of section 350.51, enter into a written agreement for the supply of property or services made on an exceptional basis by a person in that establishment, at its entrance or near the establishment, before the supply is made. The operator shall, by means of the device referred to in section 350.52, enter the prescribed information relating to the agreement.