Technical Memorandum (TM) - Scientific and technical findings that are preliminary or of specialized interest, e.g., quick release reports, working papers, and bibliographies that contain minimal annotation. Does not contain extensive analysis.
Contractor Report (CR) - Scientific and technical findings by NASA-sponsored contractors and grantees.
Conference Publications (CP) - Collected papers from scientific and technical conferences, symposia, seminars, or other meetings sponsored or co-sponsored by NASA.
Special Publication (SP) - Scientific, technical, or historical information from NASA programs, projects, and missions, often concerned with subjects having substantial public interest.
Technical Translation (TT) - English-language translations of foreign scientific and technical material pertinent to NASA’s mission.