<!- - tag elements in a request from a client application - ->
Enclose all tag elements in a request generated by a client application.
(Optional) One or more attributes of the form attribute-name="value". This feature can be used to associate requests and responses if the value assigned to an attribute by the client application is unique in each opening <rpc> tag. The NETCONF server echoes the attribute unchanged in its opening <rpc-reply> tag, making it simple to map the response to the initiating request. The NETCONF specification assigns the name message-id to this attribute.