For legal reasons, any sort of secret ID code/number that is used by the insecure legacy government/banking systems is banned from bitcointalk.org.

This includes, for example:
- US social security numbers
- Non-US government ID numbers that can cause security problems when released
- Credit card numbers

Exceptions might possibly be made if this info is absolutely essential to a scam investigation or it's very certain that you're posting secret ID codes that belong to you.