- White list: can be used as common built-in declaration
- Black list: can be used only for overrides and super-calls-
- Not considered members: ones that is not in black or white list.
Such members can be used in any context, but they usages marked as deprecated
Third kind is needed to make possible use declarations added in future JDK versions.
Deprecation is necessary because they may get into black list in next Kotlin compiler version
Ilya Gorbunov