The document applies to the installation, modification, extension and examination for and the operation of call systems, allowing to call or search for persons; moreover, additional information may be transferred. These systems are characterised in that a more or less important danger may occur to the calling person or a third party in case calls are not transferred due to a fault condition or systems faults not being identified in time. This document applies to installations in hospitals, care homes, care wards and similar institutions; elderly persons homes, sheltered accomodation; places of detention.