Some idiot at the place which may not be named has put the techies in charge of the linkability rules, and consequently I can't understand them and have to call on the help of a fellow resident to explain them. If you would like to see them, read the wiki here.
I am by no means a Mathematics-phobe, I passed my "o" level and can calculate percentages, decimals and fractions considerably better than many of my compatriots, but I read this sort of formula and some part of my brain forces me into a coma. The harder I try to understand, the more unconscious the necessary parts become, until I read the words and figures and they no longer make sense to me. Is it even written in English?
The old rules were that if you tried to link a set of prims and they were more than 30 metres apart, they wouldn't link. Nice and simple. It often failed even if things were only 6 metres apart, for no apparent reason.
Alarmingly the wiki only seems to mention linking two prims, so I expect general mayhem if wanting to link more than two. If someone writes something in plain English I'd be glad to know.