@Override
    public Element getSubsriptionErrorDetail() {
        return DocumentHelper.createElement(QName.get("not-subscribed",
                "http://jabber.org/protocol/pubsub#errors"));
    }
Subscription requests must be approved and only subscribers may retrieve items.

@author Matt Tucker
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/models/AuthorizeAccess.java