This European Standard is applicable to the establishment of the condition of drain and sewer systems byinspection, status codification and consideration of external factors and other information.It is applicable to drain and sewer systems, which operate essentially under gravity, from the point where thesewage leaves a building or roof drainage system, or enters a road gully, to the point where it is discharged into atreatment works or receiving water. Drains and sewers below buildings are included provided that they do not formpart of the drainage system of the building.This part of the European Standard specifies a coding system for the description of the internal condition of drains,sewers, manholes and inspection chambers identified through visual inspection. Where appropriate, it can also beused for pressure and vacuum systems in accordance with the requirements of the employing authority.This part of the European Standard does not generally specify requirements for carrying out inspections.