Keep Topic First Feature

Google Groups has added the ability to keep a post on top of the stack, and also to disable replies to it. While viewing a post you will see a link to "edit moderator options" and when you click on it, you will see

Close this topic

Stop any users from replying to this topic.
(Topics that have been inactive for more than 30 days will be closed automatically.)

Display this topic first
Keep this topic at the top of the topic list for easy viewing by all readers. Ideal for important announcements or informative posts.