| 556 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {3} |
| 400 | DF | .~ SILICON CONTAINING {19} |
| 427 | | .~.~ Sulfur attached indirectly to silicon by nonionic bonding {2} |
| 428 | DF | .~.~.~> Chalcogen bonded directly to sulfur |
| 429 | DF | .~.~.~> The sulfur is part of a -SH or -SC(=X)- group, wherein X is chalcogen (H of -SH may be replaced by a substituted or unsubstituted ammonium ion or a Group IA or IIA light metal) |