checked or unchecked exception when Throwable is extended

Hi
Suppose a user defined exception class, say UserExcp is created by extending the Throwable class.
What type of exception it will be checked or unchecked and why?

I wouldn't consider it either, it is not an exception if it does not extend the Exception class.

However, it must be handled accordingly (i.e. surrounded with a try/catch block or use a throws declaration, same as a checked exception).