<p>Even though a client might be available (as stated in the most recent presence stanza), the user this client belongs to might not be focused on the client currently. &xep0132; defines a method for a physical test of user presence. Since this requires special hardware that can not be assumed to be available, this XEP defines a software-only implementation where no direct feedback is expected. This is known as 'nudge' or 'buzz' in some legacy IM protocols.</p>
<p>It was discussed whether this should be part of &xep0085;. However, the semantics are inherently different, since it describes the sender's state, not a request to change the receiver's. Thus, a separate extension is desirable.</p>
</section1>
<section1topic='Requirements'anchor='reqs'>
<p>The specification addresses remotely getting the user's attention in a more assertive way than simple text messages.</p>
</section1>
<section1topic='Protocol'anchor='protocol'>
<p>In the following conversation, a user talks to somebody, but this user doesn't respond. The second inquiry includes an attention extension.</p>
<examplecaption="User sends a regular message"><![CDATA[
<p>When no reply is received, the sending user might want to grab the other's attention. This is done by sending a message that includes an <attention/> element qualified by the 'urn:xmpp:attention:0' namespace &VNOTE;. Note: The message may or may not include a &BODY; element.</p>
<li>Before sending an attention message stanza, the client SHOULD confirm support for it in the other client as described under <linkurl='#disco'>Determining Support</link>.</li>
<li>The message stanza containing the attention extension MAY contain a body and/or other extensions, which is to be displayed along with executing the attention event.</li>
<li>In message stanzas containing either &xep0203; data, attention extensions MUST be ignored, since this is an instant event which should not be replayed after a delay.</li>
<li>Messages containing an attention extension SHOULD use the headline message type to avoid offline storage.</li>
<li>Using the attention extension in &IQ; stanzas is not desirable, since this is part of the conversation.</li>
<p>If an entity supports receiving the attention extension, it MUST advertise that fact in its responses to &xep0030; information ("disco#info") requests by returning a feature of "urn:xmpp:attention:0":</p>
<p>In order for an application to determine whether an entity supports this protocol, where possible it SHOULD use the dynamic, presence-based profile of service discovery defined in &xep0115;. However, if an application has not received entity capabilities information from an entity, it SHOULD use explicit service discovery instead.</p>
<p>However, since some users might not want this feature to disturb them, a client SHOULD allow the user to disable support. When the feature is disabled, it MUST NOT be advertised in disco#info.</p>
<p>It is RECOMMENDED that only message stanzas containing attention extensions from peers on the user's roster are accepted. Finer grained control might be implemented.</p>
<p>This specification defines the following XML namespace:</p>
<ul>
<li>urn:xmpp:attention:0</li>
</ul>
<p>Upon advancement of this specification from a status of Experimental to a status of Draft, the ®ISTRAR; shall add the foregoing namespace to the registry located at &NAMESPACES;, as described in Section 4 of &xep0053;.</p>
<p>If the protocol defined in this specification undergoes a major revision that is not fully backward-compatible with an older version, or that contains significant new features, the XMPP Registrar shall increment the protocol version number found at the end of the XML namespaces defined herein, as described in Section 4 of <cite>XEP-0053</cite>.</p>