| 552 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
|
| * | DD | ORGANIC COMPOUNDS (Class 532, subclass 1) {11} |
| 271 | DF | .~ Polycyclo ring system containing anthracene configured ring system having at least one double bond between ring members and having oxygen single bonded or any atom double bonded direct at the 9- or 10-position (e.g., anthrones, anthranois, etc.) {10} |
| 276 | DF | .~.~ The polycyclo ring system has nine cyclos {3} |
| 279 |  | .~.~.~ Oxygen single bonded directly to the nonacyclo ring system {1} |
| 280 | DF | .~.~.~.~> Halogen or light metal containing or processes wherein a halogen or light metal containing is utilized |