Mike, I recall the last time I looked at object based annotations, there was a backward compatibility issue because both ends of the Marshal streams expect string based annotations as does RMIClassLoader.
However if you are still keen to investigate object based annotations there's no reason you couldn't treat a string like a char array = byte array (beware signed byte) and have a RMIClassLoaderSPI deserialize the objects after they were sent in string form? Regards, Peter. Sent from my Samsung device.