| 568 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {4} |
| 300 | DF | .~ OXYGEN CONTAINING (E.G., PERCHLORYLBENZENE, ETC.) {11} |
| 924 | DF | .~.~ Nitro containing (including aci forms) {6} |
| 927 | | .~.~.~ Benzene ring containing {4} |
| 928 | DF | .~.~.~.~> Plural rings containing {2} |
| 932 | DF | .~.~.~.~> Polynitro {2} |
| 936 | DF | .~.~.~.~> Halogen containing {1} |
| 939 | DF | .~.~.~.~> Nitro bonded directly to benzene ring {1} |