| 534 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES | 
| * | DD | ORGANIC COMPOUNDS (CLASS 532, SUBCLASS 1) {8} | 
| 573 | DF | .~ Azo {51} | 
| 809 | DF | .~.~ Exactly three azo groups attached indirectly to each other by nonionic bonding {3} | 
| 810 | DF | .~.~.~ Containing -C(=X)-, wherein X, is chalcogen or nitrogen (e.g., carbonyl, etc.) {1} | 
| 811 |  | .~.~.~.~ Nitrogen single bonded directly to the -C(=X)- group (e.g., carboxamide, guanyl, etc.) {1} | 
| 812 | DF | .~.~.~.~.~> Plural -C(=X)- groups containing |