1. A method for identifying an operation site ( 1 ) during an operation, in particular using a laser system ( 20 ), with the help of unique data ( 10 ) about the operation site ( 1 ) wherein a first copy ( 11 ) of the unique data ( 10 ) is stored in the laser system ( 20 ); the unique data ( 10 ) is located in the immediate vicinity of the operation site ( 1 ) and/or at the operation site ( 1 ); the first copy ( 11 ) and the unique data ( 10 ) are checked for their identity before the operation begins; and the result of the identity check is passed on to the laser system ( 20 ).