S.D. Codified Laws § 12-4-19.7
The voter registration list maintenance confirmation mailing notice shall be a double postcard stating that the voter's registration may be canceled if the card is not returned. In addition, the card shall state that if the information on the return card is correct, the voter shall sign and return the card by the voter registration deadline of the primary election or the voter's registration becomes inactive. The card shall also state that if the information on the return card is not correct, the voter shall send the correct information to update the voter's registration or the voter's registration becomes inactive. If the card is returned indicating a new address in another county in South Dakota or another state, the card shall serve as a cancellation authorization. The card shall also give information on reregistering if the voter has moved to another county or state. The card shall give the information about the voter as the information appears in the registration records.
SDCL 12-4-19.7