[ebxml-msg] syncReply question

A few of us here are having a difficult time interpreting the reliable
messaging paragraph.

Assume HTTP is the transmission protocol.  If syncReply (in the original
message) is "false", will the "200 OK" response be empty and all messages,
such as Acknowledgment, Pong, Status Response and the answer(s) to the
original message be asynchronous, or is it possible that, say, an
Acknowledgment may be returned with the "200 OK" response?

The interpretation problem arises when we try to interpret the statement
that the client waits on an acknowledgment.  That wait could be within the
HTTP Post/response sequence, or it could be a wait after the empty response
is received.

Any guidance would be appreciated.

Bob