What it is: A numeric signal that accompanies a verified identity, alongside the date of your last audit. It gives an application something more granular than a yes/no verified flag.
What it is not: It is not a social credit score, and it is not affected by what you post or who you talk to. It reflects identity verification, nothing else.
Who can read it: Only applications you have granted a specific sensitive-data permission to. Ordinary profile access does not include it, and the permission has to be requested explicitly at the point you authorize the app.
Where it does not follow you: Sign in with an alias and the service does not receive your Core ID at all — and with it, neither the KYC status nor the score.
Why it exists: So a service can decide what access to give you without running its own verification and collecting your documents all over again. Less duplication of your personal data, not more.
Manage what apps can see: Your settings at uiid.me