Tyres and wheel arch clearance

[qkingston]

Can anyone define exactly what the rules are ref how much tyre can protrude outside the line of the wheel arch and how far up it is measured. I'm assuming the answer is none, but it does depend on where you measure as the wheel arch tapers away as the body curves under the car. With a tiny amount of negative camber my front tyres extend 15mm outside the line of the body when measured about 2 thirds the way up the wheel arch. Do I need to get the wheel offset repdone?
VMT
QK

[Purple AK]

The rules for SVA relate to the wheel and not the tyre. Basically of you take a vertical line upwards from the rim edge at 3 o'clock and 9 o'clock (wheels in straight ahead position) The edge of the rim must not be outside of the wheel arch at those points. The tester will use a plumb bob and tape measure to test this. Tyre protrusion is not an issue