| 526 / | HD | SYNTHETIC RESINS OR NATURAL RUBBERS -- PART OF THE CLASS 520 SERIES |
| * | DD | SYNTHETIC RESINS (Class 520, Subclass 1) {8} |
| 72 | DF | .~ POLYMERS FROM ONLY ETHYLENIC MONOMERS OR PROCESSES OF POLYMERIZING, POLYMERIZABLE COMPOSITIONS CONTAINING ONLY ETHYLENIC MONOMERS AS REACTANTS OR PROCESSES OF PREPARING {43} |
| 258 | DF | .~.~ From monomer containing nitrogen atom as part of a heterocyclic ring {6} |
| 261 | | .~.~.~ Three or more nitrogen atoms in a single ring |