Per the Acord about page:
ACORD (Association for Cooperative Operations Research and Development) is a global,
nonprofit organization serving the insurance and related industries. ACORD facilitates
the development of open consensus data standards and standard forms, and works with its
members and partner organizations to drive implementation of those standards.
This page contains the latest few versions of the ACORD XML schema for property and casualty implementations. You may have to register for a free account to dowload the schemas and documentation.