Personal data: who should be considered a Russian?

Question

Law in IT

Hello!
Thinking about the idea of ​​a startup. The implementation may involve the processing of
personal data.
Interested in the question: according to the law, who should be considered "Russians"? Obviously,
only those who have a Russian passport. Hence the clarifying question:
how to filter them from the global mass? The client base is planned to be
pseudonymous: the user can enter any name (real name - optional,
verified with scans - optional).
Can someone share a dock and live cases?
Digression: It is not clear what the RKN want from Twitter and FB. The network is also pseudonymous;
documents are not asked during registration. Who is Russian for RKN?
Entered with ru ip? Specifying the Russian Federation as the country of birth / residence, but with the name John Doe?
Writing in Cyrillic? Sending notarized scans?
I will be glad to recommendations and advice except for one - "Forget it" :) This answer is already
here on the forum. I would like something a little less goofy :)

Answer 1

What does it mean how to filter? Ask the user for the country.

Answer 2

... he found himself, as it were, between a hammer and an anvil,
but since it is the hammer that hits the anvil, and not vice versa,
it is, first of all, that you have to reckon with ...
we don’t have case law
, do it in such a way that everything suits: both the individual entrepreneur, and the choice of the country, and by indirect signs (VKontakte authorization)

Answer 3

The term "Russian" is associated with self-identification and nothing more.
I will not smoke what exactly you are looking for, but I believe that you are confusing something somewhere.
Legally, you can only use the term "Citizen of country X". For example, "Citizen of Russia".