This section applies where the court dealing with an offender is required by section 268B to impose a serious terrorism sentence of detention in a young offender institution under section 268A.
The appropriate custodial term is—
14 years, or
if longer, the term of detention in a young offender institution that would be imposed in respect of the offence in compliance with section 231(2) (length of discretionary custodial sentences) if the court did not impose a serious terrorism sentence (or an extended sentence or a sentence under section 265).
The extension period must—
be at least 7 years, and
not exceed 25 years.