The message browser is very straightforward to use. It uses the current message definition file as a data dictionary to make it easy to read in a given HL7 message. Also, any python script in the Global Inbound Script window (Chameleon > Global Inbound Script) will affect the message browser's behavior. For example, if you wrote a script which removes all OBX segments and parsed the message in the message browser, your OBX segments would not appear.