So far as it is necessary for the purposes of section 222, P may determine, by a notice under this section, which of 2 or more residences (of which one is the dwelling-house) was P's main residence for any period within P's period of ownership of the dwelling-house.
A notice under this section may not vary a notice previously given under section 222(5)(a) as respects any period for which the previous notice had the effect of determining whether or not a disposed of residence was P's main residence.
In subsection (4) "disposed of residence" means one of P's residences which was disposed of (in whole or in part) before the date of the disposal mentioned in subsection (1)(a).
A notice under this section—
Where a notice under this section affects both P and an individual ("X") who was, in the period to which the notice relates ("the relevant period"), P's spouse or civil partner living with P—
Nothing in subsection (2) affects the application of section 222(5) in relation to P.