There are times when you might only want to allow certain people to post in a Feed. For example, say you want to create an "announcements-only" Feed — i.e., a Feed that only certain people can post to, but that does not require any dialogue and all people in the team should be able to view.
In this case, you can enable the "Restrict posting to Admins and Team Leads" option in the team settings for that team.
To enable this option for any team:
Go to Manage Teams:
Click on the ellipsis icon next to the Team you want to update and select "Edit team settings":
Check the box next to "Restrict posting to Admins and Team Leads":
Be sure to select "Save Changes" before navigating from the Edit Team dialog box.
Now only Admins and Leads will be able to post, but all other user types will still have access and be able to view the posts.