On 13 July 1992, the Senate Select Committee on POW/MIA Affairs levied a task on NSA/CSS to review SIGINT reporting for relevance to the Vietnam POW/MIA issue and possible correlation to individual POW/MIA cases. NSA/CSS provided the Committee with three Correlation Studies, produced in August 1992, September 1993, and September 1996. Most of the information mentioned in these studies is chronologically organized by Reference Number (RefNo), which is listed as case #, and includes the incident date. The Department of Defense assigned RefNos to each incident in which there was the potential loss of life or capture. There are some entries without a RefNo or case #, but do have the incident date. The earliest incident is dated 1951 and the last 1988.
Over the next several months, NSA/CSS will post over 1600 additional documents related to POW/MIAs in Vietnam and Southeast Asia. The documents are NSA field site reporting, NSA end product, summary reporting, memoranda, watch officers notes, and analyst communications. For ease of searching, those documents will be accessible under links posted for each RefNo for which they contain pertinent information.
The correlation studies and the documents related to the incidents have been previously released under the Freedom of Information Act (FOIA) in the past, but they have never before been posted together, facilitating access to families and historians. In addition, the documents have been reviewed using the most current guidance, making this release the most complete of any prior releases.