Recommendation ITU-T G.654 describes the geometrical, mechanical and transmission attributes of a single-mode optical fibre and cable which has the zero-dispersion wavelength around 1300 nm wavelength, and which is loss-minimized and cut-off wavelength shifted at around the 1550 nm wavelength region. This is the latest revision of this Recommendation that was first created in 1988. Version 10.0 introduces category E ITU-T G.654 fibre in order to significantly improve the optical signal to noise ratio (OSNR) characteristics to support 100 Gbit/s and beyond 100 Gbit/s digital coherent transmission systems in terrestrial deployments. It is intended to maintain the continuing commercial success of this fibre in the evolving world of high-performance optical transmission systems.