Mapped to NIST 800-171 Requirement: 3.8.3
CMMC Assessment Objective: MP.L2-3.8.3[a]
What This Control Means
When CUI is stored on media (e.g., hard drives, USBs, CDs, printed documents), it must be clearly marked or designated to reflect its sensitivity. You must identify:
• The tools or methods used to label CUI
• Whether the labeling is physical, digital, or both
• How labels are applied consistently and visibly
These markings help prevent mishandling, misplacement, or accidental disclosure.
Why It Matters
Without clear markings:
• Users may treat CUI like regular data
• Portable media could be lost or mishandled without anyone realizing it contains sensitive information
• Risk of unintentional exposure increases dramatically
• Auditors may flag systems and processes for insufficient data labeling
CUI labeling is critical for ensuring proper awareness and control.
How to Implement It
1. Identify Labeling Tools
• Physical media:
◦ Printed labels (e.g., “CUI” stickers)
◦ Permanent markers with standardized language
• Digital media:
◦ Metadata tags (e.g., classification fields in file properties)
◦ Filenames or folders labeled with “CUI”
◦ Banner headers/footers in documents or PDFs
2. Define Labeling Techniques in Policy
• Include:
◦ What should be marked
◦ When it must be marked (e.g., at creation, upon transfer)
◦ Who is responsible for labeling
3. Use Automated Tools Where Possible
• Leverage document management systems that tag files automatically
• Use labeling features built into platforms like Microsoft 365 or Adobe Acrobat
4. Standardize the Label Format
• Ensure it aligns with DoD CUI standards (e.g., “CUI//SP-Category” if applicable)
Evidence the Assessor Will Look For
• Policies outlining the labeling of CUI on media
• Examples of physical or digital media marked with CUI
• Screenshots showing labeled files, folders, or device tags
• Procedures or workflows describing how labeling is applied
• Training materials showing user awareness of labeling requirements
Common Gaps
• No labeling policy in place
• Users unaware of when or how to label CUI
• Inconsistent or informal labeling practices
• Over-reliance on filename conventions without policy support
How Cuick Trac Helps
Cuick Trac supports this requirement by:
• Defining labeling procedures as part of your media protection policy
• Providing templates and automated workflows for tagging CUI
• Supporting integrations with tools that enforce digital CUI labeling
• Helping track and audit labeled media for verification
• Ensuring users are prompted to apply labels during media creation or export
With Cuick Trac, every piece of CUI is clearly identified—by policy, system, and user.
Final CTA
If it contains CUI, it should say so.
Schedule a Cuick Trac demo to identify, label, and protect all media that holds sensitive information.