The TS_UD_CS_MONITOR_EX packet describes extended attributes of the client-side display monitor layout defined by the Client Monitor Data block (section 2.2.1.3.6). This packet is an Extended Client Data Block and MUST NOT be sent to a server which does not advertise support for Extended Client Data Blocks by using the EXTENDED_CLIENT_DATA_SUPPORTED flag (0x00000001) as described in section 2.2.1.2.1.