Merge branch 'kerrilorimer-patch1' into microsoft/azure-docs/Migrations

Author: SyntaxC4

articles/active-directory/users-groups-roles/domains-manage.md

@@ -46,6 +46,10 @@ You can add up to 900 managed domain names. If you're configuring all your domai
 
 If you want to add a third-level domain name such as ‘europe.contoso.com’ to your directory, you should first add and verify the second-level domain, such as contoso.com. The subdomain is automatically verified by Azure AD. To see that the subdomain you added is verified, refresh the domain list in the browser.
 
+Note
+
+If you have already added a contoso.com domain to an Azure AD tenant, you can also add the subdomain europe.contoso.com to a second Azure AD tenant. When adding the subdomain, you will be prompted to add a TXT record in the DNS hosting provider.
+
 ## What to do if you change the DNS registrar for your custom domain name
 
 If you change the DNS registrars, there are no additional configuration tasks in Azure AD. You can continue using the domain name with Azure AD without interruption. If you use your custom domain name with Office 365, Intune, or other services that rely on custom domain names in Azure AD, see the documentation for those services.