Inscriptions are a novel way of etching data in the form of code, images, audio, and text files onto the Bitcoin blockchain. Each inscription is tied to a so-called ordinal, representing an individual, unique satoshi (sat)—the smallest unit of Bitcoin. The term "ordinal" comes from what its inventor, Casey Rodarmor, dubbed Ordinals Theory, a proposed methodology for tracking and labeling of individual sats based on the order in which they're mined and transferred.