| 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} |
| 303 | DF | .~.~ Ketones {10} |
| 308 | DF | .~.~.~ Benzene ring containing {3} |
| 325 | DF | .~.~.~.~ Plural rings containing {3} |
| 326 | DF | .~.~.~.~.~ Polycyclo ring system {1} |
| 327 | | .~.~.~.~.~.~ Bicyclo ring system {1} |
| 328 | DF | .~.~.~.~.~.~.~> Naphthyl ring system |