World generation features sometimes have configuration for what blocks to target or to check. These come in a variety of shapes which in some cases makes it impossible or cumbersome to test certain scenarios.

List of config properties and their type

Feature	Config property	Type
block_column	allowed_placement	BlockPredicate
disk ice_patch	targets	List of BlockState
geode	cannot_replace invalid_blocks	BlockTag
glow_lichen	can_be_placed_on	List of Block
huge_fungus	valid_base_block	BlockState
netherrack_replace_blobs	target	BlockState
ore	target	RuleTest
replace_single_block	targets	RuleTest
root_system	root_replaceable	BlockTag
root_system	allowed_tree_position	BlockPredicate
spring_feature	valid_blocks	List of Block
vegetation_patch waterlogged_vegetation_patch	replaceable	BlockTag