Section 69 (1) (a) of the Road Traffic Act, 1961 provides that where a member of the Garda Síochána has reasonable grounds for believing that a mechanically propelled vehicle has been used in a public place and that the actual user of the vehicle was a particular person, he may demand the person to produce an insurance certificate, a certificate of exemption, or a certificate of guarantee in respect of the use of the vehicle.
The section further provides that if the person refuses or fails to produce the certificate then and there, he shall be guilty of an offence unless, within ten days after the day on which the production was demanded, he produces the certificate in person to a member of the Garda Síochána at a Garda station named by the person at the time at which the production was demanded.
As I understand it the law simply does not allow for the acceptance of anything other than what is set out in the Act and it is not open to the Commissioner, therefore, to issue a direction for the acceptance of anything else.