Anyone know anything about cautions and CRB and working with kids?

[Zoë]

hi i am a qualified supervisor of two to five year olds and i worked for the same pre school for just over a year, but it was poorly run and even tho i filled in my CRB form my superiors never sent it off, during this time i got a caution for harrassment (long story regarding my mother and my daughter, but too personal to go into detail on here, but it involved four voicemails i left her) i recieved a formal caution which i accepted as i admitted doing it etc.. however i am just about to apply for a job in a special needs school and am worried this will affect my chances i know i have to declare it but do i right down everything that happened on an attached letter along with the application form or do i just tick the box that asks if you have any convictions etc.. this is the only thing i have and it happened two years ago and i am 31 years old. the police sergeant at the station was very sympathetic about my case and said she felt bad giving me the caution but there was no other way round it, she said that they are allowed to write notes on any cautions they send to the register so she would do her best and said she was happy for my employer at the time to contact her (i did tell them but they werent bothered anyway!) any help would be greatly appreciated