 <p>You might be using the <strong>3.x</strong> version of jstree which does not take the rel attribute into account. If you are using the 3.x version, more information can be found at this link : <a href="https://github.com/vakata/jstree/issues/473" rel="nofollow">https://github.com/vakata/jstree/issues/473</a></p>