I'm going to let Trevor deal with that one.
While I defer that to him, the one thing, Mr. Julian, that I would point out around modelling—because we have been looking at it, as you say, for a while, for the reasons that Trevor has given—is that this delineation question is at the heart of it. There's a significant risk of revenue erosion if this exception to the surplus-stripping rule is too wide. We've had some conversations about it.
You've heard from Mr. Wark. He's just touching on the design features, the notion of how long a parent could remain involved in a business transferred to a child. There's that element. There's the element of whether they can own shares and the nature of those shares, and the extent to which the children need to be involved in the business.
Delineating what looks like a real intergenerational transfer is very difficult. If that isn't done properly, then, yes, we are saying that there is a significant risk of revenue erosion, which runs to your question about modelling.
Trevor, I don't know if you want to add anything to that.