IS29500 is an American National Standard
The INCITS Executive Board has approved the adoption of ISO/IEC IS29500 (Office Open XML) as an American National Standard this week (on April 15), and the document will be published soon by ANSI.
This action taken by INCITS is a relatively routine occurence, as the US typically adopts ISO/IEC standards as national standards. As an INCITS V1 member, I was very excited to see this news. It’s a positive step in the validation and global adoption of IS29500.