Defined schema for error namespace; modified spec to use provisional namespace before advancement to Draft (per XEP-0053).
The <dtmf/> element SHOULD possess one 'action' attribute, which MUST be either "button-up" or "button-down", specifying whether the button is being depressed or released. This allows DTMF tones to be reconstructed in real-time. If the 'action' attribute is not included, the recipient MUST assume this to be a "button-down" event, and imply a "button-up" event after a reasonable timeout (100 milliseconds is RECOMMENDED) or when another DMTF event is received.
Unless, the 'action' attribute is 'button-up', the <dmtf/> element MUST possess a 'code' attribute that specifies the tone to be generated. The value of the 'code' attribute SHOULD be one the following characters: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, #, and * -- however, the characters A, B, C, and D MAY be sent as well.
The <dtmf> element SHOULD be sent as the payload of a Jingle content-info message as illustrated in the following example.
+The <dtmf> element SHOULD be sent as the payload of a Jingle content-info message as illustrated in the following example. (See Protocol Namespaces regarding issuance of a permanent namespace.)
If an entity supports Jingle DTMF (which natively includes sending of DTMF in the XMPP signalling channel), it MUST return a &xep0030; feature of "http://jabber.org/protocol/jingle/info/dtmf" in response to service discovery information requests.
-If an entity also supports sending of DTMF in the content channel, it MUST also return a service discovery feature of "http://jabber.org/protocol/jingle/info/dtmf#rtp" in response to service discovery information requests.
+If an entity supports Jingle DTMF (which natively includes sending of DTMF in the XMPP signalling channel), it MUST return a &xep0030; feature of "http://www.xmpp.org/extensions/xep-0181.html#ns" in response to service discovery information requests.
+If an entity also supports sending of DTMF in the content channel, it MUST also return a service discovery feature of "http://www.xmpp.org/extensions/xep-0181.html#ns-rtp" in response to service discovery information requests.
The ®ISTRAR; shall include 'http://jabber.org/protocol/jingle/info/dtmf' in its registry of protocol namespaces.
+Until this specification advances to a status of Draft, its associated namespaces shall be "http://www.xmpp.org/extensions/xep-0180.html#ns" and "http://www.xmpp.org/extensions/xep-0180.html#ns-errors"; upon advancement of this specification, the ®ISTRAR; shall issue permanent namespaces in accordance with the process defined in Section 4 of &xep0053;.
The XMPP Registrar shall include 'http://jabber.org/protocol/jingle/info/dtmf#rtp' in its registry of service discovery features.
+The XMPP Registrar shall include 'http://www.xmpp.org/extensions/xep-0181.html#ns-rtp' in its registry of service discovery features.