This Recommendation describes the geometrical, mechanical and transmission attributes of a single-mode optical fibre and cable with zero-dispersion wavelength shifted into the 1550 nm wavelength region. This is the latest revision of the Recommendation that was first created in 1988. This revision clarifies chromatic dispersion characteristics in Table 2 (G.653.B). This category limits the chromatic dispersion coefficient by a pair of bounding curves vs wavelength for the range of 1460 nm to 1625 nm. The extension to these wavelengths is intended to provide information to support coarse wavelength division multiplexing applications which do not have significant non-linear impairments.