But then is not as said in documentation, the good point of the text in documentation is that you can write ONLY a substring of the external name and then the FMB204 will connect to the device with the name matching the string....
Why is needed the MAC address then?
If there's some device detected with the External name like the one configured (no matter the MAC address) the FMB204 will connect to it (or that should do as the doc says), and the FMB204 will use the MAC detected for that name...no need that the user configure each MAC address to be connected, just with the name is enough.
Then, if I do what the doc says, I can write Externalname as "EFRI" and the FMB204 should connect to any device with name like EFRIXXXXXXXXXXXX without specifying MAC address in config.
External Name parameter works as a substring, which allows user to enter a part of the full external device name. For example, if external device name is "HandsFreeHeadset" and user enters "HandsFree" in External Name parameter window, then FMB204 will be allowed to connect to an external device named "HandsFreeHeadset".