Documentation of Changes made in Open XML File Format

Hi Folks,

I have made some changes in Open XML File Format using extension list. I'm able to use files without any issue as the extension list supports full fidelity in round-tripping & interoperability.

I wanted to understand the process of documenting this changes in the public & the legal implications if any.

Is there any standardization process for the same?

Any pointers around this will be highly appreciated.

Thanks,