Multiple editions of the same standard
Sometimes a standard is published multiple times with different prefixes, such as NS-ISO/IEC and NEK ISO/IEC. The content of the documents is the same.
Some standards are published as a collaboration between multiple standardization organizations, such as ISO/IEC. Standard Norway and the Norwegian Electrotechnical Committee can also adopt ISO/IEC standards, leading to multiple editions of the same standard, such as NS-EN ISO/IEC (or NS-ISO/IEC) and NEK ISO/IEC. The content of the documents is the same.
An example of this is NS-EN ISO/IEC 27001:2023 and NEK EN ISO/IEC 27001:2023.