S.D. Codified Laws § 40-19-3
The branding of cattle, horses, mules, and buffalo shall be done by use of a hot iron. A freeze brand may, however, be applied to horses and mules. A single letter, number, figure, bar, quarter circle, half circle, or complete circle, or a half diamond, or complete diamond placed on livestock are unrecordable brands under this chapter, including new split-brands. However, presently recorded brands are valid as long as fees are paid and there is no conflict with board policy.
A single letter, symbol, or number brand is recordable for sheep. A sheep brand shall be either a hot iron brand or shall be applied with branding paint. No more than two colors or one color and a hot iron brand may be recorded for sheep under one application fee. Authorized paint colors are yellow, blue, green, black, red, or purple. No dot, bar, slash, quarter circle, circle, or the letter "Q" may be registered as a sheep brand. A brand may be recorded for the side, hip, nose, or jaw on either the left or right side of sheep. No brand may be recorded as "across the back" of a sheep. A sheep brand, regardless of position, is only recordable in a different color on the same location.
SDCL 40-19-3