| 534 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES | 
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| * | DD | ORGANIC COMPOUNDS (CLASS 532, SUBCLASS 1) {8} | 
| 573 | DF | .~ Azo {51} | 
| 660 | DF | .~.~ Hydroxy and carbonyl of -C00- bonded directly to a monocyclic benzene ring (H or hydroxy may be replaced by a substituted or unsubstituted ammonium ion or a metal) {5} | 
| 670 | DF | .~.~.~ Two azo groups attached indirectly to each other by nonionic bonding {1} | 
| 671 |  | .~.~.~.~ Sulfonic acid group containing (-(0=)S(=0)-OH, wherein H of -OH may be replaced by a substituted or unsubstituted ammonium ion or metal) {2} | 
| 672 | DF | .~.~.~.~.~> Plural monocyclic benzene rings, each having hydroxy and carbonyl of -COO- bonded directly thereto | 
| 673 | DF | .~.~.~.~.~> Additional -C(=X)-, wherein X is chalcogen |