the sinckan manuscripts (; also spelled "sinkang" or "sinkan") refers to a series of leases, mortgages, and other commerce contracts written in sinckan, taivoan, and makatao; they are commonly referred to as the "fanzi contracts" (). some are written only in a romanized script, while others were bilingual with adjacent han writing. currently there are approximately 140 extant documents written in sinckan; they are important in the study of siraya and taivoan culture, and taiwanese history in general although there are only a few scholars who can understand them.