CPV code 98112000 designates Services furnished by professional organisations in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
98112000 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 98110000 (Services furnished by business, professional and specialist organisations).