A Rail Link is a block that can be used to link rail networks, which allows signalling to become smarter in certain situations. For example, imagine the situation where you want to link two dimensions with rails. If you are not using a Rail Link, the signals cannot recognize portals. Therefore you cannot create a block section that spans rails in both dimensions. This makes it very tricky to prevent carts from colliding.

The Rail Link can be placed next to a rail that is just in front of the portal. Next up, right-click a rail just after the portal (in the other dimension) with a Rail Configurator. Right-click the Rail Link with that same Rail Configurator to bind it to the rail. Through this process, you have linked both dimensions to each other. Now, the signaling will also include rails on the other dimension to determine which carts are allowed to pass.

[crafting{200, 205, key=block/rail_link}]