The first Note is confusing and unclear: "A support beam is required on every wall of a cave tile (both sides) to prevent the tile from collapsing."
I suggest changing it to: "Support beam applies to a rock tile (Cave Wall), and turns it into a Reinforced Cave Wall, which reduces chance of collapse on open tiles bordering the reinforced one. To minimize chance of collapse on an open tile, reinforce every cave wall around it."-- [[User:Jarisleif]]