Idaho Code § 50-1740
Within twenty (20) days after preparing and issuing any delinquency certificate the treasurer shall enter the same in a book to be kept by said treasurer known as "Local Improvement District Delinquency Certificate Register," which register shall contain in proper columns, the number of the assessment, the name of the district in which assessed, name of the person to whom assessed, if known, description of the property sold, corresponding with the description in the certificate and the assessment roll, amount of assessment, penalty, and the treasurer must regularly number each entry in said register on the margin of said book and put a corresponding number on each original and duplicate delinquency certificate. Such register must contain blank spaces following each entry of a delinquency certificate therein, in which may be entered the name of an assignee thereof, the date of such assignment and the amount paid the assignee, the name of a redemptioner thereof, the date of such redemption and the amount paid by such redemptioner. Such book or register shall be retained by the treasurer and become a part of the records of his office. From and after entry in such register and until two (2) years from its date, any such certificate, unless redeemed, may be purchased from the treasurer in the manner hereinafter provided.
Idaho Code § 50-1740