When a convicted person serves one or more custodial sentences of a total duration of less than or equal to five years, the prison administration must, at least one month before the duration of the sentence served is equal to twice the duration of the sentence remaining to be served, or, if the sentence is less than or equal to six months, at the time of committal or when the sentence becomes final, inform the person that he or she is likely to benefit from compulsory release, unless he or she objects, informing him or her, where appropriate, of the interest and feasibility of such a measure.