Is Ramsay a rule or a principle?

Readers know that all statutes must be construed purposively: you must have regard to the purpose of the relevant provision and interpret its language so far as possible in a way which best gives effect to that purpose.

Readers also know that the ‘Ramsay principle’ says that the meaning which best gives effect to the purpose of a tax statute is often a wide practical meaning.

The principle is encapsulated in the often-quoted statement that ‘the ultimate question is whether the relevant statutory provision construed purposively is intended to apply to the transaction viewed realistically.’

That is to view a transaction ‘realistically’ is simply to adopt a wide practical view of the transaction; and the reason why the transaction must...