Classified National Security Information (CNSI) Guidance

From the Information Security Oversight Office (ISOO)

The National Archives and Records Administration (NARA) Information Security Oversight Office (ISOO) issues guidance to Federal agencies on classifying, safeguarding (to include marking), and declassifying national security information (CNSI).  In the list below, you can search, access, and read our current CNSI guidance. You can find additional CNSI resources, links to governing regulations, and more at the ISOO website.


Using the guidance table below:

  • You can sort the guidance list by title, type of guidance, or date, etc.
  • You can also search the list for specific terms that might be in the title, the topic, or the description, to help you find documents on a particular subject.

NARA Guidance Portal


Cancelled guidance

  • If you are looking for cancelled / expired / superseded guidance, click the link below the Current Guidance list to go to the Cancelled Guidance page.
Number Date issued Title zRIN General topic Summary Date posted to portal Status Date of status change
ISOO Notice 2021-03 10/05/2021 Applying to the Technology Modernization Fund (TMF) to support classification and declassification improvements   technology Informs agencies of the option to apply for TMF funding to support technology efforts in classification, declassification, and CUI marking and other system improvements. 10/05/2021    
ISOO Notice 2021-02 7/16/2021 Partial Waiver for the Declassification Review of Certain White House, National Security Council (NSC) and Homeland Security Council (HSC) Records   Declassification review Expands and revises waiver for declassification review that was established in ISOO Notice 2017-03. Except for certain categories, agencies do not need to refer to the NSC staff for declassification review White House, NSC, and HSC records created prior to January 20, 2009, that are designated for transfer to the National Archives after declassification. 7/16/2021 Cancels Notice 2017-03 7/16/2021
ISOO Notice 2021-01 6/29/2021 Rescinding Approval of Pre-1989 General Services Administration (GSA)-Approved Containers   containers, vaults Informs agencies that older containers and vault doors will be phased out of use for securing classified information, based on GSA rescinding approval for such old containers. 10/02/2020    
ISOO Notice 2020-03 10/02/2020 COVID-19 Emergency Authorities for Classified National Security Information   COVID-19 Reminds agencies of emergency authorities, applies those authorities to the COVID-19 pandemic, sets out limitations on authorities, and informs agencies to check this guidance periodically for updates as the COVID-19 situation evolves. 10/02/2020    
ISOO Notice 2020-02 08/24/2020 Transmitting Classified Information   Mailing Reminds agencies of requirements they must meet for sending classified information through the U.S. Postal Service (USPS) or by means of commercial carriers. 08/24/2020    
ISOO Notice 2020-01 05/12/2020 COVID-19 guidelines and alternative operating methods for alarm monitoring industry   Industrial security Outlines agency emergency authorities to establish additional security requirements, and in particular addresses alarm monitoring requirements during the COVID-19 remote operations situation. 05/14/2020    
ISOO Notice 2019-01 09/27/2019 Agencies Eligible to Receive Referrals from Automatic Declassification at 25, 50, and 75 Years   Declassification Lists agencies that the Interagency Security Classification Appeals Panel (ISCAP) has approved to receive referrals resulting from automatic declassification reviews and that may exempt specific information from automatic declassification. 02/19/2020 Cancels ISOO Notice 2015-05 09/27/2019
ISOO Notice 2018-01 01/16/2018 Declassification Date or Event Markings Clarification   Declassification Guidance on using an event for declassification and including a date that will not extend the classification period beyond the currently approved period. 02/19/2020    
ISOO Notice 2017-04 09/14/2017 Security Classification Guides   Security classification guides Outlines requirements for security classification guides and recommends a standard format for the guides to promote consistency for security classification guidance throughout the executive branch. 02/19/2020    
ISOO Notice 2017-02 04/17/2017 Clarification of Classification by Compilation   Classification decisions Outlines when a compilation of unclassified information must undergo an original classification decision and who must make that decision. 02/19/2020    
ISOO Notice 2015-01 06/05/2015 Withholding Authorities for Mandatory Declassification Review   Declassification review Describes conventions for identifying reasons an agency withholds information in response to mandatory review requests made under section 3.5 of E.O. 13526. 02/19/2020 Supersedes ISOO Notice 2009-07 06/05/2015
ISOO Notice 2014-03 08/27/2014 U.S. Protection of Information Shared by the Government of the United Kingdom   Marking Describes new United Kingdom information marking system and classification levels for protecting information from the UK. 02/19/2020    
ISOO Notice 2014-02 04/04/2014 Procurement of Security Equipment   Security equipment Informs agencies that they must purchase "GSA-approved” security containers and vault doors through GSA Global Supply utilizing the appropriate national stock number. 02/19/2020    
ISOO Notice 2014-01 03/26/2014 Appeal Rights for Mandatory Declassification Review Requests and the Rejection of Requests for Specific Reasons   Declassification review Informs agencies and requesters of the proper steps for granting appeal rights for mandatory declassification review (MDR) requests. Also addresses rejecting MDR requests for specific reasons. 02/19/2020    
ISOO Notice 2013-06 09/18/2013 Changes in Express Mail   Mailing Outlines requirements and obligations when using either the “Express Mail “ or “Priority Mail Express ” labels to mail SECRET information. 02/19/2020    
ISOO Notice 2013-05 08/19/2013 Revision of the Standard Form (SF) 312, “Classified Information Nondisclosure Agreement”   Non-disclosure agreement Notifies agencies of revisions to the SF 312 non-disclosure agreement, dated 7-2013, where to find the new form, and that previous versions are no longer valid. 02/19/2020    
ISOO Notice 2013-03 04/10/2013 Processing of Mandatory Declassification Review Requests Appealed to the Interagency Security Classification Appeals Panel   Declassification review Clarifies that agencies must continue to process mandatory declassification review (MDR) requests that have been appealed to the Interagency Security Classification Appeals Panel (ISCAP) in cases where the agency has not made a decision within one year of the filing of an initial request or within 180 days of an internal agency appeal. 02/19/2020    
ISOO Notice 2013-01 11/01/2012 Further Marking Guidance on Commingling North Atlantic Treaty Organization (NATO) and Classified National Security Information (NSI)   Marking Provides guidance on markings and declassification instructions for U.S. documents that commingle NATO information and NSI and also applies requirements to all NATO classified information, including information which requires special handling (e.g., ATOMAL). 02/19/2020    
ISOO Notice 2012-04 10/12/2012 Additional Guidance on Standards for Security Equipment   Security equipment Provides guidance on requirements to procure GSA approved security containers and eliminate non-GSA approved security containers 02/19/2020    
ISOO Notice 2012-03 04/02/2012 Additional Guidance on Supplemental Controls Required for Safeguarding Classified National Security Information   Security equipment Clarifies that supplemental controls specified in § 2001.43(b)(i) apply to both GSA approved security containers and vaults built to FED-STD 832. Also clarifies that ISOO will coordinate on safeguarding standards published by GSA (in accordance with § 2001.42(a)), for security equipment and Intrusion Detection Systems (IDS) used as a supplemental control under § 2001.43(b). 02/19/2020    
ISOO Notice 2012-02 12/23/2011 Classification Marking Instructions on the Use of "50X1-HUM" vs "25X1-human" as a Declassification Instruction   Marking Clarifies guidance on using “50X1-HUM” and discontinuing use of “25X1-human” as a declassification instruction when reusing or creating new classified documents. Applies to both original and derivative classification actions. 02/19/2020    
ISOO Notice 2012-01 12/08/2011 Requirements for Derivative Classifier Training   Training Provides guidance to agencies and contractors on identifying derivative classifiers, and requirements to receive biennial training mandated in E.O. 13526, section 2.1(d) and 32 CFR 2001.71(d). 02/19/2020    
ISOO Notice 2011-02 05/18/2011 Further Guidance and Clarification on Commingling Atomic Energy Information and Classified National Security Information   Commingling Provides further guidance on marking commingled Transclassified Foreign Nuclear Information (TFNI) and classified National Security Information (NSI), and clarifies placement of declassification instructions on single-page documents that commingle Restricted Data (RD), Formerly Restricted Data (FRD), or TFNI, and classified NSI. 02/19/2020    
ISOO Notice 2009-16 09/17/2009 Prohibited Use of Electronic Signatures on the Standard Form 312, "Classified Information Non-disclosure Agreement"   Non-disclosure agreement Clarifies that agencies should not use electronic signatures to execute the SF 312, “Classified Information Nondisclosure Agreement.” 02/19/2020 Reviewed 04/26/2010
ISOO Notice 2009-07 01/08/2009 Mandatory Declassification Review – Inappropriate Citation of Section 6.2(d) of E.O. 13526   Declassification review Clarifies that agencies should not cite section 6.2(d) of E.O. 13526, “Classified National Security Information,” when responding to requests or appeals for mandatory declassification review filed under section 3.5. 02/19/2020 Revised 09/30/2010
ISOO Notice 2009-06 12/12/2008 Handling NATO Information Identified during Automatic Declassification Processing   Declassification Provides guidance that declassification reviewers must follow when they encounter NATO information while conducting declassification reviews prior to the onset of automatic declassification. 02/19/2020 Reviewed 04/26/2010
ISOO Notice 2009-04 10/10/2008 “Best Practices” for Declassification Review Record Keeping   Declassification review Identifies “best practices” in several agencies' declassification review record-keeping procedures. 02/19/2020 Reviewed 04/26/2010
ISOO Notice 2009-03 10/10/2008 Notification, Coordination, and Documentation Related to Subsequent Reviews Conducted by Primary Reviewing Agencies [Related to Automatic Declassification]   Declassification review Provides guidance that declassification review actions considered by primary reviewing agencies require prior notification to and coordination with either: (1) the National Archives and Records Administration (NARA), for records in NARA’s physical and legal custody; or (2) the Information Security Oversight Office, for records in the legal custody of primary reviewing agencies. 02/19/2020 Reviewed 04/26/2010
ISOO Notice 2009-02 10/10/2008 Initial Instructions on the Use of the SF 715, "Declassification Review Tab"   Declassification review Clarifies that consistently and properly using SF 715, “Declassification Review Tab,” is necessary to support agency actions related to exempting, referring, excluding, and declassifying information. 02/19/2020 Revised 09/30/2010
ISOO Notice 2009-01 10/10/2008 Use of Standard Form 715, "Declassification Review Tab"   Declassification review Establishes that SF 715, “Declassification Review Tab,” is the only tab approved for working with Federal records under the automatic declassification provisions of E.O. 12958, as amended. 02/19/2020 Revised 09/30/2010
ISOO Handbook 2018-01 12/01/2010 Marking Classified National Security Information   Marking Clarifies that E.O. 13526 and 32 CFR Part 2001 prescribe a uniform security classification system that requires standard markings for classified information, and that, except in extraordinary circumstances, classified information marking shall not deviate from the prescribed formats. 02/19/2020 Revision 4 01/01/2018
ISOO Handbook 2018-02 10/01/2018 Developing and Using Security Classification Guides   Security classification guides Provides guidance for developing security classification guides. 02/19/2020   10/01/2018
ISOO Handbook 2019-01 07/01/2018 Responsibilities of the Senior Agency Official (SAO)   Responsibilities Provides guidance on E.O. 13526, Sec. 5.4(d), senior agency official responsibilities. 02/19/2020   07/01/2018
ISOO Guidance 2018-01 09/06/2018 Agency Training Requirements   Training Outlines additional training requirements for all individuals that work with classified information, including annual refresher training, annual training for original classification authorities, and biennial training for all derivative classifiers per E.O. 13526. 02/19/2020    
ISOO Guidance 2018-02 09/13/2018 Mandatory Declassification Review (MDR)   Training Clarifies that requesters must submit an MDR request in writing to the applicable agency and identifies where to find the MDR contact information for each agency. 02/19/2020    
ISOO Guidance 2018-03 09/13/2018 Classification Challenges   Classification challenges Provides guidance that agencies must establish a system for processing, tracking, and recording formal classification challenges made by authorized holders. 02/19/2020    
ISOO Guidance 2010-01 11/28/2010 OMB - WikiLeaks: Mishandling of Classified Information   Mishandling classified information Clarifies that Wikileaks types of disclosures will not be tolerated, and notifies agencies that handle classified information that they must establish a security assessment team consisting of counterintelligence, security, and information assurance experts to review the agency’s procedures for safeguarding classified information against improper disclosure, and that ISOO, OMB, and ODNI will implement procedures for evaluating agency practices as well. 02/19/2020    
ISOO Guidance 2016-02 03/17/2016 Fundamental Classification Guidance Review Checklist   Classification guidance review Provides Fundamental Classification Guidance Review guidance in the form of a checklist. 02/19/2020    

 Superseded / Cancelled ISOO Guidance