The document discusses the 400ZR specification from the Optical Internetworking Forum (OIF). The 400ZR specification aims to standardize an interface for short-reach and unamplified DWDM links using 400G/wavelength coherent modulation. Key objectives include supporting reaches over 120km, leveraging work from other standards bodies, and targeting low power pluggable modules with densities equivalent to grey client optics. The status provides details on FEC decisions, ongoing liaison activities, upcoming DSP implementations, and work maturing optical specifications and measurement methodologies.