If it is not clear what the numbers mean, it is always worth checking other documents about the same person in the Arolsen Archives. Sometimes information can be found that reveals what the numbers stand for. In this case, it helps to look at the statistical card for Zofia/Sophie Ozvatic, which reveals that 198715 was the number of the CM/1 application her father submitted for IRO support. On many DP identity cards, the number of the CM/1 application is written here. This is also sometimes referred to as the IRO number.