[gzread]

Wow. Literally right next to the birthday field, which is apparently a gateway to mass surveillance, is physical location, which is apparently not?

[liveoneggs]

https://en.wikipedia.org/wiki/Gecos_field

[iamnothere]

Why not just add national ID number then? Surely that won’t be a problem either?

[NekkoDroid]

If you wanna save it in your user record sure, why not?

Though the main problem would be that there isn't a "national ID number" everywhere in the world, so the format would be near arbitray.