| 423 / | HD | CHEMISTRY OF INORGANIC COMPOUNDS |
| 351 | DF | NITROGEN OR COMPOUND THEREOF (EXCEPT AMMONIUM SALT OF NON-NITROGEN ACID) {5} |
| 385 | DF | .~ Oxygen containing {4} |
| 395 | DF | .~.~ Nitrate {3} |
| 398 | | .~.~.~ Utilizing halogen containing reactant {1} |
| 399 | DF | .~.~.~.~> And nitric acid reactant |