3.3.5.2.8.1 Processing Z-Order Sync Support Flag
On processing the TS_RAIL_CLIENTSTATUS_ZORDER_SYNC (0x00000004) flag in the Client Information PDU (section 2.2.2.2.2), the server SHOULD create the marker window (section 3.3.1.3) and send the ID of this window to the client in the Z-Order Sync Information PDU (section 2.2.2.11.1). If the client does not advertise support for Z-order sync, then the server MUST destroy the marker window, if it exists.