I believe arg1 can be just about anything.
Are you running into problems? If so, what are you seeing?
You may need to serialize objects before sending them between SWFs.
Check out this ActionScript class on Google code for a LocalConnectionManager that retains the type information of transferred objects:
Thanks a lot,
now i can send and receive object but only beans,
is there any other trick to communicate a singleton or an object having arguments in it constructor,