Idaho Code § 25-1142
Every sheep owner may use one (1), and only one (1), brand for sheep, which brand may be recorded as herein provided. Each such sheep owner, in addition to his brand may record and use for sheep a hot iron brand on the nose or a tattoo brand on either the flank or the ear, or both a hot iron brand on the nose and a tattoo brand on either the flank or the ear. In addition to his recorded brand, hot iron brand on the nose or tattoo brand on either the flank or the ear, he may, for the purpose of distinguishing the sheep of one of his bands from the sheep of the other, use any one or more of the digits except the digit 1 and 0, which herd brand shall not be recorded. Neither of the digits shall be used on sheep except as provided in this section.
Idaho Code § 25-1142