In Sweden the authorities have run out of social security numbers because so many immigrants are "born" on 1st of january or 1st of july because those are important dates (so they are booked as being born those days even though they were not).
So social security numbers for example 1991-01-01-xxxx have run out.
Now I wonder if it would be an idea to switch to hexadecimal digits at the end? Then there can be more combinations.
I wonder if this question can fit somewhere in a programming / science context?