The definition was developed by the WHO’s Technical Advisory Group on  the Governance of the Private Sector for Universal Health Coverage, as part of the development of the WHO’s strategy report on “Engaging the private health service delivery sector through governance in mixed health systems”. The Advisory Group was set up to support WHO’s work in strengthening governance of the private sector in health, under the leadership and guidance of the WHO’s System’s Governance and Stewardship Unit, and is now working to provide strategic guidance on the implementation of the WHO Strategy Report.