CreateFragment adds a page to the space or contest being addressed and returns its id. The parent and the slug are what make the page reachable: they place it in the tree and the path follows from them, and the parent has to exist. A page marked as a draft is visible to admins only, which is how a page can be written before members are meant to see it. A fragment carrying a link instead of content is an entry pointing elsewhere: it takes a place in the tree and a title, nothing is rendered at its path, and a reader who opens it is sent to the url.