This document specifies requirements for using identifiers in distributed ledgers including blockchains. These requirements supplement those of ISO 8000-115. The following are within the scope of this document: – requirements for each identifier in distributed ledgers including blockchains, where the ledger enables supply chains to exchange transaction data; – requirements for the off‑ledger data set that is referenced by an identifier in a distributed ledger. The following are outside the scope of this document: – requirements for implementing distributed ledger technology including blockchains; – requirements for technology to ensure immutability of data sets; – requirements for the processes of creating identifiers; – requirements for the processes of creating the content of off‑ledger data sets; – requirements for the processes of creating immutable data sets.