The following referenced documents are indispensable for the application of this document. 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 10000-1, OPC Unified Architecture - Part 1: Overview and Concepts
http://www.opcfoundation.org/UA/Part1/
OPC 10000-3, OPC Unified Architecture - Part 3: Address Space Model
http://www.opcfoundation.org/UA/Part3/
OPC 10000-4, OPC Unified Architecture - Part 4: Services
http://www.opcfoundation.org/UA/Part4/
OPC 10000-5, OPC Unified Architecture - Part 5: Information Model
http://www.opcfoundation.org/UA/Part5/
OPC 10000-19, OPC Unified Architecture - Part 19: Dictionary References
http://www.opcfoundation.org/UA/Part19/
UN/CEFACT: UNECE Recommendation N° 20, Codes for Units of Measure Used in International Trade