The support for custom tabs is only applicable to the main OC client window at this time, not the individual chat windows themselves.
Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
Hi Dear all:
Does anyone know how to build the sample function? as follow (the info is from the
OCS 2007 Evaluation Guide)

we can see page 34 that descibes "Tabs in Conversation Windows New Extensible conversation window, which can host applications as well as controls whereby the URL to host is sent in a SIP INFO message"