Bookmarking posts
Every post has a bookmark action. Tap it to save the post to your Bookmarks; tap again to remove it. Bookmarking is private - no one else can see what you've saved, and the author isn't notified.
Open Bookmarks from the menu to see everything you've kept, most recent first. It's the place to stash a post you want to read properly later, or one you suspect you'll want to find again.
If a post you bookmarked is later deleted by its author, it simply drops out of your list.