CPV code 90680000 designates Beach cleaning services in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
90680000 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 90600000 (Cleaning and sanitation services in urban or rural areas, and related services).