What kind of "proof of foreign residence" is accepted/expected for a BritRail pass, which is only available to non-UK residents?
The conditions for the pass say that I have to provide such a proof when validating the pass, and whenever challenged to do so by a ticket inspector. I'm somewhat at a loss as to what it is they expect to see. I'll be carrying my (Danish) passport, of course, but supposedly they're looking for residence rather than nationality.
Various places on the net suggest a driver's license, but I don't have one.
The best I can think of is my Danish health insurance card ("sygesikringskort"). At some level, the fact that the Danish government extends tourist health insurance to me is arguably evidence that they consider me resident here ... but most of the text on the card is in Danish, and I doubt a random UK railway employee would even know what it is.