Essential elements for such a planning instrument have been identified according to international good practice (Box 2.3). Transparency and predictability in development control mechanisms will increase the credibility of the city master plan and help to promote private investment under the plan. Viet Nam has a unique land ownership system with Land-use Rights (LURs) (Box 2.4), and development control in urban areas is based on zoning. Effective enforcement is another urgent challenge (see Chapter 4).