Windows 10 build 20200

Windows 10 build 20200 is a build of Iron, the 21H1 development semester of Windows as a service. Two screenshots of this build was posted to GitHub repository of Windows Package Manager by a Microsoft employee on 27 August 2020. The full buildtag was later shown in a comment under an issue posted to GitHub repository of Windows Terminal by another Microsoft employee on 8 December 2021.

It was also mentioned in the metadata file  when updating to build 20201.