3.3.5.2.1.2 Sending HandshakeEx PDU
The HandshakeEx PDU MUST be constructed as specified in section 2.2.2.2.3.
If Enhanced RemoteApp has been enabled for the current RAIL session (section 3.3.5.1.3), the server MUST set the TS_RAIL_ORDER_HANDSHAKEEX_FLAGS_HIDEF (0x00000001) flag. If it has not been enabled, the server MUST NOT set this flag.
If Enhanced RemoteApp is not enabled, and support for the HandshakeEx PDU was not indicated in the Remote Programs Capability Set (section 2.2.1.1.1), the server MUST send the Handshake PDU (section 3.1.5.1) instead of the HandshakeEx PDU.