Seems that early versions of Windows Active Directory would offer a default path name of “corp” during setup. Back in the days before the Internet became a part of everyday life, many admins accepted this without thinking too much about it. But once you start connecting servers to the Internet, they are liable to do DNS lookups on names like this, and accidentally connecting to something like “corp.com”. So to avoid such a name from coming under the control of less-than-savoury elements, Microsoft has bought it over <https://www.theregister.co.uk/2020/04/08/microsoft_active_directory/>. One of the reader comments links to this old Microsoft blog post <https://devblogs.microsoft.com/oldnewthing/20061013-05/?p=29393>, which explains that example/default names like “Contoso” and “Fabrikam” used in Microsoft’s documentation and products were actually created by their legal department, after a careful vetting process to ensure that they are indeed entirely fictitious.