Hide a Page from Students
From time to time you may want to keep students from viewing pages or even know they are there, this can be accomplished by checking the Hide this Page from Students box while editing the page. Click the Save Changes button and students will no longer see the page.

When looking at the list of pages hidden pages will be italicized to indicate that they are hidden.
Locking Discussion Topics
To prevent further posts to a discussion topic:
To prevent further posts to a graded discussion topic after the due date:
In this situation the Close for Comments button disappears after the due date passes. If you need to stop students from posting to the discussion topic you will need to perform some additional steps to close the topic.