What control marking is used on classified military information disclosed to a specific foreign country?

The designation "REL TO" is a control marking that indicates classified military information is authorized for disclosure to a specific foreign country or countries. This marking is an essential part of the foreign disclosure process, as it specifies the conditions under which the information can be shared, ensuring it is kept within the appropriate boundaries of international relations and security protocols.

Using "REL TO" communicates that the information is sensitive and must only be handled by the intended recipient nation(s), reflecting the U.S. Department of Defense's commitment to protecting national security interests while also collaborating with allied nations. It prevents unauthorized dissemination and reinforces accountability concerning who can access the information, thereby facilitating more effective international partnerships while ensuring compliance with U.S. disclosure policies.

Other control markings like "CONFIDENTIAL," "FOR OFFICIAL USE ONLY," and "SECRET" refer to levels of classification but do not specifically address the foreign disclosure aspect. They indicate the sensitivity of the information itself rather than the permissions or restrictions related to sharing with other nations. Therefore, "REL TO" is the most accurate option in this context for designating classified military information shared with a specific foreign country.