Nuclear Suppliers Group (NSG), one of the international multilateral export control systems, has designated Trigger List Item and Nuclear Dual-Use Item as control items. The Trigger List Item includes the “Especially Designed or Prepared (EDP)” term as control context. This term is very subjective and vague. Why this ambiguous term reflected in the control context? The EDP term is one of the essential elements of multilateral nuclear export controls since the NPT came into effect in 1970. The EDP concept is the basis of the rules in the Trigger List of NSG Part 1. NSG control items and contexts are decided through consensus among Participate governments, and there are three main reasons for reflecting EDP term in the guideline. First, it is to expand the control network by preventing the diversion of concerned traders. Secondly, technology development is faster than the regulatory speed, and it is tough to put all the items on the list. And last, it is to control other sensitive information such as concerned traders’ shopping list. To reduce the ambiguity of EDP, the US, UK, and Canada presented their interpretation methods at LEEM, a sub-group of the NSG. The United States and Canada have four location criteria (inside the containment building, RCS system or control, RCS system attachment, outside the containment building) and three purpose criteria (custom-made for nuclear power, whether it is an item according to the nuclear industry standard, not made to order) to determine the EDP items. The United Kingdom considers the original design intent and the purpose for which the item was originally designed. They also think about the nature of any specific or unique design features in terms of an item’s “fit,” “form,” and “function” that determine EDP item. Currently, in the case of KINAC, although it is not a controlled item in Korea, items designated by other countries are controlled as EDP items, and detailed standards for parts are prepared and controlled as EDP items. The interpretation of TL’s EDP differs from country to country, and differences are allowed between member states to some extent. Suppose Korea, like the US, UK, and Canada, examines measures to control EDP and reflects it after benchmarking. In that case, it is expected that it will contribute to reducing the export control loopholes for advanced technologies in the future and improve nuclear transparency through strict implementation of Korea’s export controls.