If you look at the full list, it seems like it's just autocompleting words in the dictionary. Here's some examples: if.corp.microsoft.com my.corp.micro

If you look at the full list, it seems like it's just autocompleting words in the dictionary. Here's some examples: if.corp.microsoft.com my.corp.microsoft.com one.corp.microsoft.com year.corp.microsoft.com baby.corp.microsoft.com pain.corp.microsoft.com crisis.corp.microsoft.com improvement.corp.microsoft.com devil.corp.microsoft.com animal.redmond.corp.microsoft.com I don't any of these some of those are actual subdomains...