Hi Juergen, thank you.
In my system if I run : getent group
I find the group nogroup : nogroup:x:65534:
If I try to add the user: nobody to the group: nogroup
the output is:
nobody already exist.
trying to understand the usefulness of this, I found something here:
https://askubuntu.com/questions/329714/what-is-the-purpose-of-the-nobody-user