In either the AAA or BB component there is something about the gender.
But it does mean that there is a limit of people born per day of a certain gender.
But for a given year, using a moniker will only delay the inevitable. Sure, there are more numbers, but still limited as there are SOME parts that need to reflect reality. Year, gender (if that's still the case?) etc.
BB is a mod-97 checksum. The first A of AAA encodes your gender in an even/odd fashion, I forgot if its the first or last A doing that.
MM or DD can be 00 if unknown. Also MM has +20 or +40 in some cases.
If you know someones birth date and gender, the INSZ is almost certainly 1 in 500 numbers, with a heavy skew to the lower AAA. Luckily, you can't do much damage with someones number,unlike an USA SSN (but I'd still treat it confidential).
Estonian isikukood is GYYMMDDNNNC, and is relatively public. You can find mine pretty easily if you know where to look (no spoilers!). It’s relatively harmless.
Kazakh IIN is YYMMDDNNNNNN (where N might have some structure) and is similarly relatively public: e.g. if you’re a sole proprietor, chances are you have to hang your license on the wall, which will have it.
It’s a bit more serious: I’ve got my mail at the post office by just showing a barcode of my IIN to the worker. They usually scan it from an ID, which I don’t have, but I’ve figured out the format and created a .pkpass of my own. Zero questions – here’s your package, no we don’t need your passport either, have a nice day!
(Tangential, but Kazakhs also happen to have the most peculiar post office layout: it looks exactly like a supermarket, where you go in, find your packages (sorted by the tracking number, IIRC), and go to checkout. I’ve never seen it anywhere else.)
YY.MM.DD-AAA.BB
In either the AAA or BB component there is something about the gender.
But it does mean that there is a limit of people born per day of a certain gender.
But for a given year, using a moniker will only delay the inevitable. Sure, there are more numbers, but still limited as there are SOME parts that need to reflect reality. Year, gender (if that's still the case?) etc.