Ahh, a little more research seems to suggest that there was no formal policy, simply that local Magistrates when dealing with petty crime might suggest that this could be an alternative that the boy and/or his parents may wish to consider. In which case the Magistrate might then be persuaded to limit or suspend the penalty and await the outcome.
The key was that the local Magistrate would know the local petty criminals and be an a position to mete out a much stiffer penalty if they came before him again.
Thanks,
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