Public, Private and Org-wide teams
In Microsoft Teams there are three types of team, Public and Private and Org-wide.
Public means anyone in the organisation (tenant) can join the team at any time without any approval
Private means owners of the team must admit new members.
Org-wide, which is a special type of team that automatically adds everyone in the organisation organization to be a part of a single team for collaboration. You can make more than one Org-wide team should you want to. Only Global admins can create an org-wide team by using the Teams client. This is up to 10,000 members at the time of writing. Note: org-wide teams aren’t yet available for Teams for Education.
I’m not in love with the public and private as these types have no bearing as to there being external guests (from other organisations/tenants) in the team. Open and Closed might make more sense, but it is what it is.
When creating them you get to choose
If you choose “From scratch”, you can then choose your type
Microsoft Teams team Discoverability
“Discoverability” used to refer to the team being visible in the “directory” of teams when you go “join or create a team”
It used to be public teams would always show in search and the directory but private teams could be configured to be shown or hidden.
“Hidden” means hidden from end-users in teams. Admins can still see the teams in Teams Admin Center (TAC) or via PowerShell.
Recently Microsoft changed this, now the discoverability option does not show under the “edit team” options. Private teams are always hidden from the directory and public teams are always shown. All documentation related to discoverability has been removed (for example this link from the TAC now redirects to the generic documentation (here)
All existing private teams are hidden from search and the directory, regardless of their previous discoverability state.
Be sure to subscribe to the blog for updates on this as I get further information.
In 2018, Microsoft considered going the other way with this, making all private teams discoverable, but later changed their mind. I think making them all discoverable would have definitely been a mistake,
The PowerShell parameter still exists, but I expect will be depreciated.
There is also another “visibility” option that can be set if you create teams from Microsoft Graph API, “Hiddenmembership”. This is different from discoverability but is also legacy.
This seems to be retired/unused, you can check if you have any via PowerShell
get-team -Visibility HiddenMembership | Format-Table -AutoSize
Changing the Privacy Type of a Microsoft Teams team
Owners of the team can later chance this “Privacy Type“ by going to “…” / Edit Team