| 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} |
| 700 | DF | .~.~ Hydroxy containing (H of -OH may be replaced by a Group IA or IIA light metal) {10} |
| 840 | DF | .~.~.~ Acyclic {16} |
| 913 | DF | .~.~.~.~ Purification or recovery {8} |
| 917 | | .~.~.~.~.~ By sorption |