Green’s Dictionary of Slang

(Aus. teen/und.) in Pentridge Prison, the Young Offenders’ Group.

2004		(con. 1960s-70s) T. Taylor Top Fellas 26/1: We already had one of the gang up there [i.e youth raining] and a couple in the Yogs, the Pentridge young offenders unit.
2016		https://www.rssing.com 29 Dec. 🌐 The University of Crime at Youth Training Centre, (YOGS Jail) .
2020		precious-testimonies.com 🌐 I was to go to ‘J-division’ otherwise known as the 'YOGS' (Young Offenders Gaol).