Type-B (Reversed): In Type B polarity, the positions of the Tx and Rx fibers are reversed at one end of the connection. This means the fiber at position 1 (P1) on one connector aligns with position 12 (P12) on the opposite connector, and so on. Patch cord polarity defines the directional optical path between two transceivers, ensuring that the transmit (Tx) signal from one device reaches the receive (Rx) port of the other. Because fiber duplex links rely on matched transmit-receive alignment, polarity determines how cables, connectors. Half the duplex patch cords I've come across don't even have A/B markers, let alone different colors on the fitting boots. In Method A, two types of patch cords are used to correct the polarity.