SDCL § 40-19-9: Rejection of brand adding symbol to existing brand--Exception.

The board shall reject any brand that has, in addition to being the same as one previously registered, any of the following marks, whether placed across, above, below, at either side or encircling the main brand: a straight bar, a quarter, half or entire circle, half or entire diamond, unless one or more of such marks is filed by the current owner of the first registered brand, in which case it may be accepted.