The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments and errata) applies.
OPC 10000-4, OPC Unified Architecture - Part 4: Services
OPC 10000-5, OPC Unified Architecture - Part 5: Information Model
UN/CEFACT: UNECE Recommendation N° 20, Codes for Units of Measure Used in International Trade, available at https://www.unece.org/cefact/codesfortrade/codes_index.html