score:7
That refers specifically to the Australian Document of Identity, which is a complicated and obscure legal fudge primarily intended to let people travel to Norfolk Island without a passport:
https://en.m.wikipedia.org/wiki/Australian_Document_of_Identity
Norfolk Island is an Australian territory that, until very recently, was largely self-governing and excluded from most Australian taxes and benefits. The government needed a way to track people traveling there, but couldn't insist on a passport (since it's not a foreign country), hence the DOI.