| 568 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {4} |
| 18 | DF | .~ SULFUR CONTAINING {9} |
| 61 | DF | .~.~ Thiol or mercaptide containing (i.e., -SH or -SM containing where M is a Group IA or IIA light metal) {5} |
| 65 | | .~.~.~ Halogen containing |