1
No.
Subdomains follow the usual domain requirements:
Use only these characters:
a-z (case-insensitive)
0-9
- (not as a starting or ending character)
Label must 63 characters ("octets") or less and names must be 255 characters ("octets") or less.
For more information, see RFC 1035.
1
Assuming you're talking about Windows networking: No.
By definition, a workgroup has no central authority. A domain is rooted in Active Directory which requires central authority.
1
Putting it simply, Google or any other name servers are going to have to recurse to .et nameservers in order to access any information in them; if they collectively block Google, then any URL-based requests will fail, as name resolution will fail.
This is an overly simplistic answer of how, but it’s possible.
Only top voted, non community-wiki answers of a minimum length are eligible