CPV code 22420000 designates Stamp-impressed paper in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
22420000 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 22400000 (Stamps, cheque forms, banknotes, stock certificates, trade advertising material, catalogues and manuals).