Index - U
| Unavailable | Network.Xmpp |
| UndefinedCondition | Network.Xmpp |
| UnexpectedRequest | Network.Xmpp |
| unlistenIQ | Network.Xmpp |
| unStream | Network.Xmpp.Internal |
| Unsubscribe | Network.Xmpp |
| Unsubscribed | Network.Xmpp |
| UseConnection | Network.Xmpp |
| UseHost | Network.Xmpp |
| UseRealm | Network.Xmpp |
| Username | Network.Xmpp |
| UseSrv | Network.Xmpp |