======Update Command======
This command is being sent by the server to a subscriber whenever a node in the subscribed sub-tree is changing one of its attributes.

<code>
<subscription id> update <node id> <attribute> <value>
</code>
  * The ''subscription id'' is the id of the node on which the subscription was originally made.
  * The ''node id'' is the id of the new node.
  * The ''attribute'' is a text referring one of the defined [[attr:overview|attributes]].
  * The ''value'' is a string which may be enclosed in double-quotes if it contains any white-space or special characters.