The SFD Graphic represents the excreta produced by the total population of an urban area from the point where it originates. It therefore includes excreta from households, schools, institutional toilets, hospitals, workplaces etc. The places where excreta originate are known as categories of origin in the SFD Manual (see Volume 1, section 5.2.1, Version 2.0). Excreta flows may need to be split between different categories (for example home and school) and these must be clearly stated in the report.