Factorio Forums

https://lua-api.factorio.com/latest/typ ... yRule.html

area - seems to be the area around the entity center that must have tiles that conform to the rules.

required_tiles - entity will be buildable on any tile that collides with the specified collision mask.

colliding_tiles - entity will not be buildable on any tile that collides with the specified collision mask.

remove_on_collision - not sure what this one does.

area does not need to be around entity center, but it is relative to it
remove_on_collision not sure, but it seems like whether tiles are allowed to be changed after entity placement. For example offshore pumps can be landfilled over and they have remove_on_collision=false, but thrusters cannot have platform foundation behind them and have remove remove_on_collision=true