A Special Envoy of the Secretary-General (SESG) is a senior United Nations official appointed by the United Nations Secretary-General to deal with a set of specific issues.
Examples include the SESGs on Children affected by Armed Conflict, on HIV/AIDS in Africa, on LRA-affected areas, on indigenous people,to a specific country etc. Bill Clinton, a president of the United States, was named the special envoy to Haiti. There are many other people of different backgrounds who serve the Secretary-General.