The Library of Congress holds a few rare Batak manuscripts at the Asian Division, which are listed in the section below. These holdings are all handwritten pustaha (accordion-folded manuscripts) that come from the homeland of the Batak peoples in northern Sumatra, Indonesia. Pustaha are divinatory manuscripts used by Batak datu, who are ritual specialists. They often discuss astrology and magic for preserving and destroying life. Some are small and portable and contain diagrams or calendars that are used to identify auspicious days. Others are large and have illustrations, and instructions for various methods of divination and describe charms, mantras, and magical devices. The manuscripts are written in the old esoteric Hata Poda language on pages made of the inner bark of the alim tree, and usually have hard covers made of wood or bone. The Batak manuscripts at the Asian Division are undated but might date to the late 1800s or early 1900s.