the court considers appropriate to satisfy the requirements for retribution and deterrence F1....

(4)Those matters are—

(a)the seriousness of the offence, or of the offence combined with other offences of which the person is convicted on the same indictment as that offence,

(b)any previous conviction of the person, and

(c)where appropriate, the matters mentioned in paragraphs (a) and (b) of section 196(1) of the 1995 Act.

[F2(4A)As respects the punishment part in the case to which subsection (4) relates, the court is to ignore any period of confinement which may be necessary for the protection of the public.]

(5)Those matters are—

(a)any period of imprisonment which the court considers would have been appropriate for the offence had the court not imposed a sentence, or made an order, such as is mentioned in subsection (3)(b) for the offence, F3...

(b)the part of that period of imprisonment which [F4would represent an appropriate period to satisfy the requirements of retribution and deterrence,] [F5and]

[F5(c)where appropriate, the ones mentioned in paragraphs (a) and (b) of section 196(1) of the 1995 Act.]

[F6(5A)But—

(a)in the application of subsection (5)(a), the court is to ignore any period of confinement which may be necessary for the protection of the public,

(b)subsection (5)(b) is subject to section 20A,

(c)subsection (5)(c) is inapplicable until the court has made the assessment required by virtue of subsection (5)(a) and (b).]

(6)An order specifying a punishment part must specify the punishment part in years and months.

(7)It does not matter that a punishment part so specified may exceed the remainder of the person's natural life.

(8)An order specifying a punishment part constitutes part of a person's sentence within the meaning of the 1995 Act for the purposes of any appeal or review.