What is a police warning?
If you are in the UK, then a police warning is officially called a Final Warning. Basically, its the kids version of an adult Caution. The only real difference is that under 18s get two chances (a reprimand and a final warning) unless the offence is more serious then you get a straight warning. The things to remember are tghat a Final Warning is not a conviction and as such you will not have a criminal record. The police will always have access of it but on your 18th birthday, it will get wiped off your record to everyone else. Not sure what this work book is but that sounds like that is a Youth offending Team thing not a police thing.