| D | SK | TEXTILES; PAPER |
| D21 | USK | PAPER |
| D21 | KL | PAPER-MAKING; PRODUCTION OF CELLULOSE |
| D21B | UKL | FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT |
| D21C | UKL | PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR |
| D21D | UKL | TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE [5] |
| D21F | UKL | PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON |
| D21G | UKL | CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES (winders or rewinders for finished products, means for adjustment of wrinkles or lateral extensions B65H) |
| D21H | UKL | PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C , D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR [5] |
| D21J | UKL | FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE (manufacture of articles by dry processes B27N) |