This is why if GB leaves the EU it will take many years to create new treaties. Civil servants and lawyers build whole careers on corner cases. In electronics, it’s like trying to decide what is a component, a sub-assembly and a finished product (which tend to attract different regulations.) It is obvious till the lawyers get involved.
It has been said of one senior English QC that he earns several million pounds a year by confusing the Supreme Court*, so you get the picture.
*With admiration, by another member of his chambers, I would add.
