Lock a discussion forum or topic to prevent learner replies and posts. This is also a good option when you want to stop any posts and replies so you can grade discussions.
Visible with access restricted: The forum or topic is visible to learners before or after the start or end date, but they cannot access it.
Visible with submission restricted: The forum or topic is visible to learners before or after the start or end date and they can access it, but they cannot post new threads or replies. This effectively makes a discussion read-only.
Hidden: The forum or topic is hidden from learners until the start or end date. Calendar events for Availability Start and Availability End are hidden until the start or end date. Notifications are also not sent until the start or end date.
Add availability dates to Calendar: Add the start date and end date of your discussion to the course Calendar.