https://docs.os.uk/os-downloads/addressing-and-location/addressbase-fundamentals/release-notes
Release Notes | OS Download Products' Documentation
release notes osdownload
https://docs.os.uk/os-downloads/topography/os-mastermap-topography-layer/release-notes
Release Notes | OS Download Products' Documentation
Release notes listed here provide information about the current release of the OS MasterMap Topography Layer product and the previous nine releases.
release notes osdownload