I thought long and hard before making my original post. We are soon to have our own intranet forum, so I'm told, but in the mean time we need to share information. If as individuals we make our own enquiries, though very willing they will get completely snowed under at BOH. And there are, I'm sure, some experts who can shine even more light on this confusing subject.
I'm absolutely not trying to smear or complain. I just think it all needs to be out in the open - and this is the only forum available so far.