Why

@JvmSynthetic

is not applicable for classes?

synthetic

means the field/method is only accessible through reflection what would that mean for a class? only available through

ClassLoader

stuff? seems weird

That's definitely not true,

synthetic

means not visible from source. You can't use it when you're writing code, but the compiler can and often does emit bytecode that makes use of synthetic things.

Out of curiosity, why do you need this?

To hide internal declarations from Java, since we don't have package-private.