This location previously contained the pre-final/draft of FAPI-RW / FAPI1-Advanced.
The final approved version of that document can be found here:
https://openid.net/specs/openid-financial-api-part-2-1_0.html
The latest working version of the document (which may contain errata not yet officially published) can be found here:
https://bitbucket.org/openid/fapi/src/master/FAPI_1.0/openid-financial-api-part-2-1_0.md