9.4.3 Propagation token
The Propagation Token is not user specific and thus not part of the Subject. A default PropagationToken is stored on the thread of execution for applications. WebSphere Application Server propagates this PropagationToken downstream and the token stays on the thread context. When a request is sent outbound to another server, the propagation token on that thread is sent with the request and the token is executed by the target server.