Thanks, TruB.
But maybe Apple’s use of it is the first time many ordinary users will meet it, and it has to be filled in to use VPN under one of the modes, and yet no info about what should be entered there in the manual or on Apple’s site. What “p####s” me off is that large companies such as Apple and Microsoft should provide necessary info so we know what it is referring to .
It’s not my passion to have to spend hours trying to find out.
PS Incidentally clicked your xgx link, but seems not to work.