Classification Guide for SIGINT Material Dating from 16 August 1945 - 31 December 1967

Document Date: December 21, 2011
Release Date: June 18, 2014
Agency: Press
Document Type: Internal NSA Documents/Presentations

Schedule for different categories of classification to be adopted for Signals Intelligence (SIGINT), which comprises information obtained through electronic surveillance, between August 1945 and December 1967.