Required?: YES

This is a version identifier for the version of the proxy tool server that generated the XML. When you update your proxy tool server in a way that changes the XML you should update the version in this XML. If you merely update your server internals without changing this XML then there is no need to change the version.

While there are no rules governing the contents of this version aside from length (cannot be greater than 32 characters), it is recommended to keep the version numeric and incremental.