element:order

If there are multiple instances of a token, element defines an ordering method.

For example, one can order his FIFA ticket tokens in his wallet by team, by date/time, by event's venue or by how many seats each token has.

For another example, a subway token represents the right to display an ad in the subway LED at a certain point of time, on certain day, for a certain duration.

There might be 4 <order> elements which allow the instances of the tokens to be ordered by hour-of-the-day, duration, subway-name, date.

It goes closely together with <group> element, which is important for backpacks (see General Nomenclature for backpack)