Division 5.4 In exceptional cases, where vehicles are designed for conditions of use which are incompatible with the characteristics of tyres of class C1, C2 or C3 and it is therefore necessary to fit tyres with different characteristics, the requirements of paragraph 1.1 of this Annex shall not apply, provided that all of the following conditions are met:

the tyres shall be approved according to either UNECE Regulation No 75^f1 or UNECE Regulation No 106^f2; and

the type-approval authority and technical service are satisfied that the tyres fitted are suitable for the operating conditions of the vehicle. The nature of the exemption and motivation of acceptance shall be stated in the test report as well as under the remarks on the type-approval certificate.