Please find below some reference materials:
- USA 18F: https://github.com/18F/open-source-policy/blob/master/CONTRIBUTING.md
- UK GDS : http://gds-operations.github.io/guidelines/
- Canada British Columbia : https://github.com/bcgov/BC-Policy-Framework-For-GitHub
- Linux Foundation: https://github.com/linuxfoundation/cii-best-practices-badge/blob/master/doc/criteria.md
This is a wiki, do not hesitate to complete or discuss other materials below