The guideline applies to all drinking-water installations on premises and in buildings. Its application to all other drinking-water installations is intended, especially to mobile installations, e.g. on ships. It contains guidance for planning, erecting, commissioning, use, operation and maintenance of any drinking-water installation. The significance of drinking-water installations for healthy living and working requires the involvement of, and agreement between, all parties involved in the planning, erection, operation and maintenance. The overall responsibility lies with the entrepreneur as defined in the German drinking-water ordinance (user or owner). Hygiene as defined by this guideline is the total of all efforts and measures taken so as to prevent indirect or direct effects adverse to health and impairments of comfort for the individual user. The guideline aims to maintain unobjectionable drinking-water quality in the drinking-water installation.