2.2.3.3.4 X-ClientInfo Header Field

The X-ClientInfo header field MUST be a combination of a globally unique value in the format of a GUID followed by a decimal counter (for example, "{2EF33C39-49C8-421C-B876-CDF7F2AC3AA0}:123"). The GUID portion of the X-ClientInfo header MUST be unique across all client instances and MUST be the same for all requests from a client instance. The client MUST use a different decimal counter when establishing a new Session Context with the server endpoint. The client can use the same decimal counter when re-establishing a Session Context with the server endpoint. The client MUST send this header on every request and the server MUST return this header with the same information in the response back to the client.