| 423 / | HD | CHEMISTRY OF INORGANIC COMPOUNDS |
| 414 | DF | CARBON OR COMPOUND THEREOF {3} |
| 415.1 | DF | .~ Oxygen containing {5} |
| 419.1 | DF | .~.~ Carbonate or bicarbonate {5} |
| 421 | DF | .~.~.~ Alkali metal containing (Li, Na, K, Rb, or Cs) {5} |
| 426 | | .~.~.~.~ Densifying soda ash |