In order to trace possible chains of infection, all participating trade and service providers and their employees will be registered electronically. All relevant private contact details (first and last name, full address, telephone number, e-mail address, as appropriate), time of attendance and, as appropriate, ticket number (Section 3 Paragraphs 1 and 2 of the SARS-CoV-2 Infection Protection Ordinance) are recorded / documented and will be made available exclusively to the health authorities if there is a justified need (in compliance with data protection). Consent to data storage must be obtained in each case (in accordance with the provisions of the GDPR).