Surat Batak is the name of the alphabet used to write languages of Angkola-Batak Mandailing, Karo-Dairi Pakpak, Simelungun, and Toba. Batak alphabet was still cognate with other characters such as Surat Ulu archipelago in Bengkulu and South Sumatra, Surat Incung in Kerinci, and Had Lampung. This alphabet has several variant forms, depending on the language and region. This alphabet must be known by the datu, the person who is respected by the people of Batak as master of sorcery, fortune-teller, and determinant of special dates or community calendar. Now, this alphabet can still be found in a variety of books of traditional Batak society.