PURPOSE AND SCOPE This Telecommunications Systems Bulletin (TSB) is intended to provide installation guidelines for maintaining polarity of transmit and receive fibers in optical fiber cabling systems. These guidelines are intended for cabling installations regardless of the connector type (simplex or duplex types)@ the number of cross-connects@ or the inclusion of an interconnect. This TSB expands upon the description of reverse-pair positioning within ANSI/TIA/EIA-568-B.1@ sub-clause 10.3.2.