In other situations in which we've had to deal with this problem, we've usually made reference to persons dealing non-arm's-length. It could be, for instance, a corporation that's dealing non-arm's-length with a charity. Under definitions in the Income Tax Act, there could be something in the statute that tells you when they're dealing non-arm's-length, but failing that, if they're dealing non-arm's-length as a question of fact, then you've established that link.
I don't actually know whether or not that's what you want to get at here.