Substitute

The Substitute algorithm replaces all blocks of one type with another. It is a "helper" algorithm - not intended for actually placing ores but rather to remove the ores placed by Minecraft and other mods so that CustomOreGen can generate them instead.

Substitute Algorithm
The Substitute algorithm scans each chunk and replaces every "replaceable" block (usually an ore) with an "ore" block (usually smooth stone, despite the name).

Distributions are generated in the order that they appear in the config file, after the vanilla generation and (hopefully) all other mods. A substitute distribution should therefore be able to replace or remove anything placed by the vanilla terrain generator, another mod, or another distribution above it.

The  element creates a distribution using the Substitute algorithm. The  element creates a non-generating distribution that can be used as a source of default parameters.

Attributes
The Substitute algorithm may have the following attributes:

Settings
The Substitute algorithm has no numerical settings.

Ore Blocks
 elements can be used to specify a mixture of ore blocks to spawn with fractional weights. The total weight of all ore blocks must be less than 1.0.

Replaces
 elements can be used to change which blocks a Substitute distribution will replace (the default is to replace nothing).

Biome
 elements can be used to customize which biomes a Substitute distribution will generate in (the default is all biomes).