This section applies in a case in which section 264 applies where—
the offender is released on licence under this Chapter,
the aggregate length of the terms of imprisonment mentioned in section 264(1)(a) is less than 12 months, and
those terms include one or more terms of imprisonment ("short transitional terms") which were imposed in respect of an offence committed before the day on which section 1 of the Offender Rehabilitation Act 2014 came into force, as well as one or more terms imposed in respect of an offence committed on or after that day.
The offender is to be on licence until the offender would, but for the release, have served a term equal in length to the aggregate of—
the custodial period in relation to each of the short transitional terms, and
the full length of each of the other terms.
In this section "custodial period" has the same meaning as in section 264.