What these letter and numbers means: [virtual-signal=signal-1](any number) number of rails going in same direction [virtual-signal=signal-S] Straight Rail [virtual-signal=signal-D] Diagonal Rail [virtual-signal=signal-W] Switch Rail [virtual-signal=signal-C] Curve Rail [virtual-signal=signal-R] Roundabount [virtual-signal=signal-T] T junction [virtual-signal=signal-4] 4 Way junction [item=roboport] Roboport included