Note in the last line, [PIDF Document]stands for the Presence Information
Data Formatdocument that will be described in the following sections.
Presence Information Data Format
The Presence Information Data Format (PIDF) is a standard [17] for minimal
presence information. PIDF is based on the model for presence and IM [18]
where the structure of presence information has been defined, as shown in Fig-
ure 13.7.
PIDF is best understood using an example.
In this example, the presence information says the entity someone@example
.comis online (open), is busy, and home. The presence document says further
that the preferred contact is [email protected], but Don’t
Disturb Please!and it also says it in French, Ne derangez pas, s’il
vous plait. A timestamp is associated with this document. An even higher-
contact priority (1.0) is to use e-mail to [email protected]. This contact
is also online. A final note says, I’ll be in Tokyo next week.
<?xml version=”1.0” encoding=”UTF-8”?>
<presence xmlns=”urn:ietf:params:xml:ns:pidf”
xmlns:im=”urn:ietf:params:xml:ns:pidf:im”
xmlns:myex=”http://id.example.com/presence/”
entity=”pres:[email protected]”>
<tuple id=”bs35r9”>
<status>
<basic>open</basic>
<im:im>busy</im:im>
<myex:location>home</myex:location>
</status>
<contact priority=”0.8”>im:[email protected]</contact>
<note xml:lang=”en”>Don’t Disturb Please!</note>
<note xml:lang=”fr”>Ne derangez pas, s’il vous plait</note>
<timestamp>2001-10-27T16:49:29Z</timestamp>
</tuple>
<tuple id=”eg92n8”>
<status>
<basic>open</basic>
</status>
<contact priority=”1.0”>mailto:[email protected]</contact>
</tuple>
<note>I’ll be in Tokyo next week</note>
</presence>Presence and Instant Messaging 233