team=! filter won't work (will affect everyone on the server)

Basically, I read on the minecraft wiki that team= filter has three options:
team='teamname' which will filter players from specified team
team='empty' which will filter players who are not in any team
team=!'teamname' will exclude players from specified team from executed command
So far on my server team= and team=teamname work good, but team=!teamname will just select everyone.
Help! Am i just being silly cuz of trusting the misleading wiki or is something wrong here? Is there any way of selecting only players who do not belong to a specified team?