A virtual presence client needs information to display people who meet. It needs
a name, an image, maybe an animated avatar, and more. This document describes
the storage and exchange of public user identity data. The virtual presence
identity data format is optimized for VP applications, where many people need
the publich data of their peers, some only once, some repeatedly, where changes
happen frequently and must be propagated quickly with minimum bandwidth.
VPTN-3: User Data