Pin Posts to Feeds (Generally Available)
Where: This feature is available in Lightning Experience in Contact Manager, Group, Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions.
Who: Admins can enable post pinning and assign pinning permission through Setup. When post pinning is enabled, admins and group owners and managers can pin posts. Other users can pin posts after you have assigned them permission.
Why: Increase post visibility with pinned posts. Pin up to three posts to the top of group and topics feeds.
How: In your org, go toand select Allow post pinning. After you enable post pinning for your org, admins, group owners, and group managers can pin posts. You can also assign the Pin Posts in Feeds permission to selected users. Assign post pinning permission in Setup through user profiles and permission sets.