I am one of the organizers of this Coalition. We expect to publish technical specification in Q1 2022. It will be a github repo and include the specs behind the common file format called OCF (Open Cap Table Format).
I am one of the organizers of this Coalition. for the first version of our open format we're focused on American Delaware Corp C's - most common entity that VCs invest into.
we announced a number of new Coalition members yesterday who also would like to see this sort of standardization outside of the US. we're focused on the US atm