Is there any directory server in public use?

[Tankman 六四 <weiwu.zhang@awallet.io>]

Hi everyone

Can you give an example of directory server used by governments or
certain authorities as to the source of truth? E.g. whether or not the
person named so exists, or whether or not the land registered at
certain street address belong to a Mr Smith?

I'm asking for this because I'm researching how the source of truth is
made publically available in a public database with a set of open
query method (like openldap filter) before the invention of
blockchain. I personally also want to see such effort being made by
willing authorities.

Thanks in advance!