Most of the tablets date from the mid-7th to mid-8th century, but some are as late as the early modern period.
[2] They were used for informal purposes, such as shipping tags, memoranda, and simple messages, and thus complement official records transmitted on paper.
[1][2] In August 1988, some 50,000 tablets from the early 8th century were found during the excavation for a department store in Nara.
The site turned out to be the residence of Prince Nagaya, a minister of the Nara court, and the tablets have improved historians' understanding of the period.
The texts are typically short and more informal than the poetry and liturgies that make up the main corpus of Old Japanese.