public class ExampleMod implements ModInitializer {
	
	//public static final Logger LOGGER...
	public static final RegistryKey<PlacedFeature> CUSTOM_ORE_PLACED_KEY = RegistryKey.of(RegistryKeys.PLACED_FEATURE, new Identifier("examplemod","ore_custom"));

	@Override
	public void onInitialize() {

		//Your other code here...

	}
}