When is a municipal guard entitled to check your ID?

A guard cannot check documents for reasons different than the ones mentioned above. Before beginning of a search, a municipal guard is obliged to specify his or her rank, give name and surname, and provide the cause of the check. Identity may be determined on the basis of a document with a picture (an ID card, a passport etc.), or on the basis of a statement of another person, identity of whom has been determined on the basis of a relevant document.