[Samba] Samba domain groups

["Bjørn Fahnøe"]

When I do a 
net groupmap list
I get
Domain Admins (S-1-5-21-1760016482-394088656-2614712563-512) -> root
Domain Admins (S-1-5-21-1941513877-1053742263-1100610399-512) -> -1
Domain Admins (S-1-5-21-57081839-3644741509-3819056003-512) -> -1
Domain Guests (S-1-5-21-1760016482-394088656-2614712563-514) -> nogroup
Domain Guests (S-1-5-21-1941513877-1053742263-1100610399-514) -> -1
Domain Guests (S-1-5-21-57081839-3644741509-3819056003-514) -> -1
Domain Users (S-1-5-21-1760016482-394088656-2614712563-513) -> users
Domain Users (S-1-5-21-1941513877-1053742263-1100610399-513) -> -1
Domain Users (S-1-5-21-57081839-3644741509-3819056003-513) -> -1

Why is there 3 groups of every kind?
I have not done anything to get them.
Can I delete the groups that is not mapped to unixgroups with Webmin?
Or shall I let them exist and not bother about them?
Bjørn Fahnøe