No, I suggested to create an user with any name you want, but with uid=4294967294 and gid=4294967294
(uid is user identification number, gid is group identification number)
It is just for testing... You could name it nfsnobody
Do you already have a nfsnobody user set in your /etc/passwd file ?
Check with : grep nfsnobody /etc/passwd
...if it returns something