Minn. Stat. § 154.14: CERTIFICATES OF REGISTRATION AND TEMPORARY PERMITS TO BE DISPLAYED.

Every holder of a certificate of registration as a registered barber shall display the certificate or permit, with a photograph of the certificate or permit holder that meets the same standards as required for a United States passport, in a conspicuous place adjacent to or near the chair where work is performed. Every holder of a certificate of registration as an instructor of barbering or a temporary permit as an instructor of barbering shall display the certificate or permit, with a photograph of the certificate or permit holder that meets the same standards as required for a United States passport, in a conspicuous place within the barber school that is accessible to the public. Every holder of a certificate of registration as a barber school and of a barber shop registration card shall display it in a conspicuous place within the establishment that is accessible to the public.