(2)If a letter is addressed to an inmate who is not entitled under the rules to receive it, it may, unless the Superintendent decides to allow the receipt thereof by the inmate concerned, under sub-rule (4) of rule 15, be withheld and kept in Superintendent's custody until the inmate is entitled to receive it or is discharged when it shall be delivered to him or it may be returned to the sender with an intimation that the inmate is not entitled to receive it.
