Rounit is an unregistered user. You can see this in the user profile.

[![Snapshot of Rounit's user profile][1]][1]

Unregistered users are no listed in the [Users][2] lists.

References

- https://meta.stackexchange.com/q/49764/289691
- https://meta.stackexchange.com/q/134415/289691

Related

- https://meta.stackexchange.com/q/192191/289691


  [1]: https://i.sstatic.net/MWCAU.png
  [2]: https://superuser.com/users