In phrases like page twenty-five, year nineteen ninety-nine, Half Life Two or article seven three zero zero one, the number is in cardinal form, but it doesn't refer to the amount of the head noun. It is used to identify a specific instance of an entity, but unlike ordinal numbers it does not always necessarily order those instances (article 73001 doesn't make one think of the 73001st article in a line of articles).
Is there a linguistic term for these numbers?