At the very top of your Browser page, there is a horizontal menu with these options:
Home : Forums : IRC Chat : User Control Panel : Search : FAQ : View new posts
Go to the one that says Search, and click on it.
There you will be asked several important things. The most important is the field where you enter your Search Query. That is where you should type this:
"UMS" or "Message System"
You should read the results, and click on related threads. You will probably find the answer to your question in a thread that already exists.
also, do the same thing for "caterpillar system"
"Caterpillar" is jargon people use around here when they mean you can see the entire party on the navigation screen, following the leader, in a chain. Like a caterpillar.