| 568 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {4} |
| 8 | DF | .~ PHOSPHORUS CONTAINING {5} |
| 13 | | .~.~ Sulfur or oxygen containing {1} |
| 14 | DF | .~.~.~> Sulfur or oxygen bonded directly to phosphorus {1} |