If—
an offender subject to a criminal behaviour order will be under the age of 18 at the end of a review period (see subsection (2)),
the term of the order runs until the end of that period or beyond, and
the order is not discharged before the end of that period,
a review of the operation of the order must be carried out before the end of that period.
The “review periods” are—
the period of 12 months beginning with—
the day on which the criminal behaviour order takes effect, or
if during that period the order is varied under section 336, the day on which it is varied (or most recently varied, if the order is varied more than once);
a period of 12 months beginning with—
the day after the end of the previous review period, or
if during that period of 12 months the order is varied under section 336, the day on which it is varied (or most recently varied, if the order is varied more than once).
A review under this section must include consideration of—
the extent to which the offender has complied with the order;
the adequacy of any support available to the offender to help the offender comply with it;
any matters relevant to the question whether an application should be made for the order to be varied or discharged.
Those carrying out or participating in a review under this section must have regard to any relevant guidance issued by the Secretary of State under section 341 when considering—
how the review should be carried out;
what particular matters the review should deal with;
what action (if any) it would be appropriate to take as a result of the findings of the review.