Currently within a Mattermost server, the highest tier of organization are Teams. However, Teams are not self-contained, and even if it is configured so that users cannot join other teams/channels, users are still aware of other users outside of their respective Teams and can also communicate with one another.

It could be useful to have another tier above Teams, for example Clients (for servers that serve enterprise clients). Each Client will have its own ID, and within it their respective teams, channels and users. Each Client will be separate from one another, meaning that the users from one Client cannot see or interact with users from another Client.