Maintenence Agency Portal
Japan Constrcution Machinery and Construction Association (JCMA) is designated by ISO/TMB to serve as the Maintenance Agency (MA) for ISO 15143 series standards.
(ISO 15143 Part 1, Part 2, Part 3 and Part 4)
https://www.iso.org/maintenance_agencies.html
What does the Maintenance Agency do?
Typically, changes to ISO publications are handled through correction, revision or amendment procedures laid out in ISO Directives. However, some portions of ISO 15143 series standards/techncal specifications include detail schema data which may require frequent updating. If the proposed changes to the schema data are known to have limited impact to the standard, or simply additions to data elements, the MA will process those new schemas to be reviewed and approved by SMEs, and the approved files will be posted at MA's website. The approved files will eventually be implemented to ISO publication through convention ISO correction, revision or amendment process.