[Simple] Adding a telephone number to a basic PIDF document

My apologies if I have addressed this to the wrong alias, but I am
having a PIDF problem which I need help with.  My goal is to add a user
specified phone number to an existing PIDF document format.  I do not
wish to make a SIP endpoint available for A/V calls, just to tell people
how to dial my PSTN number.  My starting point is a basic PIDF document
like the following-

<presence xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:ep="urn:ietf:params:xml:ns:pidf:status:rpid-status"
xmlns:et="urn:ietf:params:xml:ns:pidf:rpid-tuple" 

xmlns:ci="urn:ietf:params:xml:ns:pidf:cipid" entity="sip:foo@bar.com">

  <tuple id="0">

    <status>

      <basic>open</basic>

      <ep:activities>

        <ep:activity>away</ep:activity>

      </ep:activities>

    </status>

  </tuple>

  <ci:display-name>Foo Bar</ci:display-name>

</presence>

Excluding the option of vcard, I assume that I need to add this phone as
a device.  So I add a device tuple.  Since I have nothing more reliable
to use than the telephone number, it is used in both the id attribute
and the deviceID element.  Draft-ietf-simple-presence-data-model-05
doesn't state explicitly as far as I can tell, but reading between the
lines I don't think I can have a device without an associated deviceID
element pointing to it from a service.  I also assume that the 'note'
element for device is interpreted differently from a note for person or
under the 'presence' root so that the note is merely a descriptor of the
device.  I only assume this because I don't see a better candidate for
describing the device.  Assuming that, my original document is modified
as follows-

<presence xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:ep="urn:ietf:params:xml:ns:pidf:status:rpid-status"
xmlns:et="urn:ietf:params:xml:ns:pidf:rpid-tuple" 

xmlns:ci="urn:ietf:params:xml:ns:pidf:cipid"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
entity="sip:foo@bar.com">

  <tuple id="0">

    <status>

      <basic>open</basic>

      <ep:activities>

        <ep:activity>away</ep:activity>

      </ep:activities>

    </status>

  <dm:deviceID>tel:+4255551234</dm:deviceID>
 </tuple>

  <ci:display-name>Foo Bar</ci:display-name>

 <dm:device id="4255551234">
   <dm:deviceID>urn:tel:+4255551234</dm:deviceID>
   <dm:note>Home Phone</dm:note>
 </dm:device>

</presence>

Is this how other folks are implementing this?

Thanks for your feedback,

Tim Rang