For simplicity's sake we refer to all Volity users as "table.html" class=wikipagelink>table, a player might be simply observing, rather that sitting in a seat and actually playing.
Like all over Volity (and Jabber) entities, every player is uniquely identified by its JabberID. The base part of a player's JID (that is, everything before the resource string) is used as a key for all bookkeeper-level lookups, as with the reputation system.