| B | SK | PERFORMING OPERATIONS; TRANSPORTING |
| B31 | KL | MAKING PAPER ARTICLES; WORKING PAPER (making layered products not composed wholly of paper or cardboard B32B; handling thin material, e.g. sheets, webs, B65H) |
| B31B | UKL | MAKING BOXES, CARTONS, ENVELOPES, OR BAGS (incising, scoring, in general B26D 3/08; combined making and filling B65B) |
| B31C | UKL | MAKING WOUND ARTICLES, e.g. WOUND TUBES (characteristics relating to the working of plastics B29; shaping of plastics or substances in a plastic state B29C) |
| B31D | UKL | MAKING OTHER PAPER ARTICLES (manufacture by dry processes of articles made from particles or fibres consisting of wood or other lignocellulosic or like organic material B27N; making layered products not composed wholly of paper or cardboard B32B; making cardboard or paper D21F , D21H , making articles from wood pulp D21J) |
| B31F | UKL | MECHANICAL WORKING OR DEFORMATION OF PAPER OR CARDBOARD (cutting, trimming, in general B26; incising, scoring, in general B26D 3/08; making layered products not composed wholly of paper or cardboard B32B; multi-ply material of paper or cardboard, its manufacture D21H) |