When magistrates or judges ask the probation service to prepare a PSR they usually (though not always) give an indication of the type of sentence they are considering. If this indication is custody the probation service will provide non-custodial options (provided the offence is not one where custody is inevitable) for consideration. These options may include community based sentences, or suspended sentences with community based “requirements attached.
Judges and magistrates are under no obligation to go along with such proposals in the report as the matter of sentencing rests entirely with them. However they should say in open court when sentencing why the various alternatives have been rejected.