An offence specified in Schedule 1 to the Children and Young Person Act (Northern Ireland) 1968 M1, except offences of common assault or battery or in the case where the offender was under the age of 20 at the time the offence was committed, an offence contrary to section 5 or 11 of the Criminal Law Amendment Act 1885 (unlawful carnal knowledge of a girl under 17 and gross indecency between males) M2.