| 528 / | HD | SYNTHETIC RESINS OR NATURAL RUBBERS -- PART OF THE CLASS 520 SERIES |
| * | DD | SYNTHETIC RESINS (Class 520, Subclass 1) {23} |
| 271 | DF | .~ FROM CARBOXYLIC ACID OR DERIVATIVE THEREOF {10} |
| 272 | DF | .~.~ From di- or higher ester of a polycarboxylic acid as sole reactant, or from a polycarboxylic acid or derivative with a compound containing two or more hydroxyl groups or salts thereof {15} |
| 302 | DF | .~.~.~ Two or more carboxylic acid or derivatives or mixtures thereof {2} |
| 305 | | .~.~.~.~ Each of the carboxylic acids or derivatives contains an aryl group |