| C | SK | CHEMISTRY; METALLURGY |
| C01 | USK | CHEMISTRY |
| C01 | KL | INORGANIC CHEMISTRY |
| C02 | KL | TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE |
| C03 | KL | GLASS; MINERAL OR SLAG WOOL |
| C04 | KL | CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES [4] |
| C05 | KL | FERTILISERS; MANUFACTURE THEREOF [4] |
| C06 | KL | EXPLOSIVES; MATCHES |
| C07 | KL | ORGANIC CHEMISTRY [2] |
| C08 | KL | ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON |
| C09 | KL | DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR |
| C10 | KL | PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT |
| C11 | KL | ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES |
| C12 | KL | BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING |
| C13 | KL | SUGAR INDUSTRY [4] |
| C14 | KL | SKINS; HIDES; PELTS; LEATHER |
| C21 | USK | METALLURGY |
| C21 | KL | METALLURGY OF IRON |
| C22 | KL | METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS |
| C23 | KL | COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL [2] |
| C25 | KL | ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR [4] |
| C30 | KL | CRYSTAL GROWTH [3] |
| C40 | USK | COMBINATORIAL TECHNOLOGY [2006.01] |
| C40 | KL | COMBINATORIAL TECHNOLOGY [2006.01] |
| C99 | KL | SUBJECT MATTER NOT OTHERWISE PROVIDED FOR IN THIS SECTION [2006.01] |