When starting a new process instance through K2 webservice you can optionally include info about Priority with value of 0-3 which is described here in K2 online help.

But "help" just states that "the priority to assign to the process instance" and not one word about if it actually does anything else.

I know that the priority field of Activities are only to give a user some visual indication about priority in there task list. 

But what is priority of the process itself used for?