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Backgrounder on standardization work done on Presence
Several attemps at standardizing presence information has been done before in several organization. Presence could be seen as a subset of context description. If there is a need for standardization of a presence or context ontology, previous work should be considered.
Differences in standards, proprietary presence definitions and lack of semantics, applications trying to use these standards have interoperability problems. If W3C should define a presence or context ontology, such as OPO, existing work should be considered in order to ease interoperability and not cause further fragmentation.
IETF SIMPLE WG
The SIMPLE WG has produced several RFCs on presence description formats.
Open Mobile Alliance
OMA has produced presence spec in both the IMPS (Wireless Village) and the PAG Working Group, the latter using and extending PIDF.