| 534 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES | 
| * | DD | ORGANIC COMPOUNDS (CLASS 532, SUBCLASS 1) {8} | 
| 573 | DF | .~ Azo {51} | 
| 588 | DF | .~.~ Process utilizing azo compound as reactant {13} | 
| 589 |  | .~.~.~ Formation of quaternary ammonium or hydrazinium group |