Sch 3 para 18
An offence under section 3 of this Act (sexual assault) if— (a) where the offender was under 18, he is or has been sentenced, in respect of the offence, to imprisonment for a term of at least 12 months; (b) in any other case— (i) the victim was under 18, or (ii) the offender, in respect of the offence or finding, is or has been— (a) sentenced to a term of imprisonment, (b) detained in a hospital, or (c) made the subject of a community sentence of at least 12 months.