What are XML Definitions
Some phone buttons can be defined using an XML definition. An XML definition is a ruleset (defined trough an XML syntax) specifying a particular setting behavior.
For example you can customize key leds colors and behavior, actions taken during a key pressure (and the key release too), also you can instruct the phone to subscribe a SIP resource and then parse the XML body received into the in-dialog NOTIFY. The XML definition can setup various states and the phone can react to state changes and/or take action in different states.
How to configure an XML Definition on a phone key
In order to configure a key with an XML definition, click on Function Keys and configure the following:
Type: XML Definition
Number: copy and paste the text of your XML definition, then Save