| 558 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {21} |
| 303 | DF | .~ Nitriles (i.e., compounds having cyano bonded directly to carbon, which carbon may be single bonded to any atom but may be multiple bonded only to carbon) {21} |
| 304 | DF | .~.~ With preservative or stabilizer {1} |
| 305 | DF | .~.~.~ Acyclic or alicyclic carbon to carbon unsaturation in the preserved or stabilized nitrile {2} |
| 307 | | .~.~.~.~ Sulfur or phosphorus containing preservative or stabilizer |