03.08.04: Media Marking

The 03.08.04: media marking requirement means you must label or otherwise clearly identify media that contains CUI so people handle, store, transmit, and dispose of it correctly. Operationalize it by defining what “marked” means for each media type (paper, removable drives, backups, portable devices), implementing the marking method, and keeping repeatable evidence that marking is performed and enforced. ¹

Key takeaways:

• Define a media marking standard that covers physical and digital media that stores or transports CUI, including exceptions.
• Embed marking into workflows (print, export, backup, removable media issuance) so it happens by default.
• Keep audit-ready artifacts: your standard, inventory mappings, samples, and periodic checks tied to systems handling CUI.

03.08.04: media marking requirement work is rarely “hard,” but it is easy to fail in an assessment because teams treat it as a policy statement rather than an operational control. Assessors look for two things: (1) a clear organizational rule for how you mark media that contains CUI, and (2) proof that the rule is followed across the media you actually use in your CUI environment. ¹

“Media” is broader than USB drives. It includes paper outputs, external drives, portable endpoints used to store files offline, and media created for backup and recovery. Marking is also broader than slapping a sticker on a laptop. Depending on the medium, “marking” can be a physical label, a header/footer, a cover sheet, a file naming convention, embedded metadata, or a system-enforced banner. Your job as CCO/GRC lead is to set a standard that people can follow quickly, then build checks that catch the places CUI can slip onto unmarked media. ¹

This page gives requirement-level implementation guidance you can apply immediately, with an evidence package designed for assessments against NIST SP 800-171 Rev. 3. ¹

Regulatory text

Requirement: “NIST SP 800-171 Rev. 3 requirement 03.08.04 (Media Marking).” ¹

Operator interpretation: You need an implemented process to mark media containing CUI so the marking communicates the handling expectations. The framework text is short, so the assessment focus becomes practical: “Show me your marking rules, show me where CUI exists on media, and show me examples where the media is marked the way your rules require.” ¹

Plain-English interpretation (what the control is really asking)

If CUI ends up on something that can be carried, copied, printed, stored offline, or shipped, you must make that “thing” visibly identifiable as CUI-bearing so personnel apply the right safeguards (storage, transport, access control, sanitization, disposal). Marking reduces accidental mishandling by people outside your immediate team (mailroom, help desk, facilities, subcontractors) and supports incident response by making scope clearer. ¹

Who it applies to (entity and operational context)

This applies to nonfederal organizations handling CUI in support of federal work, including federal contractors and their downstream third parties where CUI flows into their environment. Practically, it applies wherever your organization:

• Creates CUI (engineering, contracts, program management)
• Stores CUI (file shares, collaboration platforms, endpoints, backup systems)
• Outputs CUI (printers, exports to PDFs, reports)
• Transfers CUI (removable media, shipped drives, offline handoffs)
• Recovers CUI (backups, DR media, archival restores)
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What you actually need to do (step-by-step)

Use this sequence to get from “policy intent” to “assessor-ready control.”

1) Define “media” in scope for your CUI environment

Create a scoped list that matches how your teams work, not an abstract definition. Include:

• Paper printouts and physical folders
• Removable storage (USB, external HDD/SSD, SD cards)
• Portable endpoints that store files locally (laptops used offline, tablets if applicable)
• Backup media (tape, offline storage exports, immutable backup copies if moved to separate media)
• Virtual media or images where CUI is packaged for transfer (ISO images, VM exports, forensic images)
  Then map each item to the systems or workflows that generate it. This mapping becomes a key assessment artifact. ¹

2) Write a media marking standard that is unambiguous

Your standard should answer, for each media type:

• What marking is required (label text, banner, footer, cover sheet, filename prefix, metadata tag)
• Where the marking appears (front cover, top/bottom of each page, drive label, device asset tag + “CUI stored” indicator)
• Who applies it (end user, IT, print services, records team)
• When it must be applied (at creation, before export, before transfer, before shipment, before storage in a cabinet)
• What exceptions exist (e.g., “marking not technically feasible” cases) and the compensating steps required
  Make the rules short enough to follow under time pressure. If you need nuance, put it in an appendix and keep the “do this every time” section crisp. ¹

3) Align marking content with your CUI handling rules

Marking only helps if it triggers correct handling. Cross-reference your CUI handling guidance so the mark implies:

• controlled storage location
• restrictions on sharing/printing
• transport requirements
• sanitization and destruction requirements
  This does not require you to invent new categories; it requires internal consistency between “what the label says” and “what people must do next.” ¹

4) Implement marking methods by medium (make it default where possible)

Below is an operator-focused implementation checklist.

Paper

• Configure standard cover sheets for CUI packets.
• Set printer defaults for CUI-capable queues to add header/footer banners where feasible.
• Require secure print/release where CUI is printed, and include marking in the print workflow instructions.

Removable drives

• Require physical labels for any removable media approved for CUI transfer.
• Tie issuance to ticketing: “Drive serial X issued to user Y for purpose Z; drive labeled per standard.”
• Block unapproved removable media through endpoint controls where feasible, and document any exceptions with compensating controls.

Portable endpoints

• If laptops store CUI locally, mark the device (asset tag or case label) according to your standard so it is treated as CUI-bearing equipment during moves, repair, or disposal.
• Add OS login banners or file classification prompts only if they map cleanly to your marking standard and you can show evidence of consistent operation.

Backups and archives

• Identify whether CUI is included in backup sets, then ensure the backup media (or the export package) is marked at the container level and tracked in inventory.
• If backups are “logical” (stored in a managed service), treat the “media marking” requirement as an identification requirement: document how the backup set is labeled/tagged in the system of record and how operators can tell it contains CUI.
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5) Train the people who touch media, not just the security team

Targeted training beats generic annual training. Ensure these groups have role instructions with examples:

• Engineering/program teams that print or export deliverables
• IT/help desk handling device repair, reimaging, and decommission
• Records/facilities teams managing storage rooms and shredding bins
• Any third party that may receive, transport, store, or destroy your media containing CUI (include contract language and handling instructions)
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6) Build a simple verification loop (so you can prove it works)

Assessors will ask “how do you know the marking is done?” Create a lightweight operational check:

• Periodic spot checks of printed output areas and file share export workflows
• Inventory reconciliation for removable media and backup media
• Ticket sampling for device disposal/reassignment to confirm “CUI-bearing” marking and sanitization steps were followed
  Document findings and corrective actions. Evidence of detection and remediation often matters as much as the initial policy. ¹

7) Package the evidence for assessment readiness

Daydream (or any GRC system) becomes useful here if it helps you keep one mapped record that ties:

• policy/standard text
• the in-scope media list
• owners
• operating procedures
• recurring evidence samples
  The practical goal: answering assessor requests in minutes, not days, without rebuilding your story each time. ¹

Required evidence and artifacts to retain

Keep artifacts that prove both design (your rules) and operation (your rules are followed):

Design artifacts

• Media Marking Standard (approved, versioned)
• CUI scope statement for systems and data types, plus a mapping to media types
• Procedures/runbooks: printing, removable media issuance, backup handling, device lifecycle (onboarding/offboarding/disposal)
• Third-party handling language where third parties touch your media

Operating evidence (samples)

• Photos/scans of marked paper outputs (headers/footers, cover sheets)
• Photos of labeled removable drives (with serial number visible) or inventory records referencing label IDs
• Tickets showing issuance, transfer, and return/disposal of removable media
• Backup inventory entries or system screenshots showing labeled/tagged backup sets containing CUI
• Spot-check logs and remediation tickets when marking was missing or incorrect
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Common exam/audit questions and hangups

Expect these questions, and pre-answer them in your control narrative:

1. “What media types are in scope for your environment?” If you hesitate, you look unprepared.
2. “Show me examples of marked media from actual operations.” Have samples ready.
3. “How do you handle CUI on backups?” Many teams forget backups are media.
4. “What prevents unmarked removable media use?” If you cannot block it technically, show governance: approvals, inventory, and checks.
5. “What happens when marking is not feasible?” You need a defined exception path with compensating handling steps.
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Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails	Fix
Policy says “mark media” but no one knows how	Ambiguous requirement leads to inconsistent practice	Publish a one-page standard with examples per media type 1
Only paper is marked	Removable media and backups create blind spots	Expand scope list to all media that can store/transport CUI 1
Marking exists, but there’s no evidence	Assessors can’t verify operation	Keep a recurring sample set: tickets, photos, inventory exports 1
“We rely on users to remember”	Human memory is not a control	Build marking into workflows: templates, default printer banners, issuance process 1
Exceptions are informal	Exceptions become the normal path	Create a documented exception request with expiration and review 1

Risk implications and why auditors care

Unmarked media containing CUI increases the chance of:

• accidental disclosure through misrouting, improper disposal, or untracked transfer
• incomplete incident scoping (you cannot quickly identify which media contained CUI)
• weak chain-of-custody for removables and backups
  For CUI programs, these issues quickly turn into reportable incidents, contractual noncompliance, and assessment findings tied to your ability to protect CUI on nonfederal systems. ¹

Practical 30/60/90-day execution plan

Use phases to move fast without guessing timelines.

Immediate (start now)

• Name an owner for the media marking standard and an operational owner in IT/operations. ¹
• Build the in-scope media list for your CUI environment and identify where each media type is created. ¹
• Collect a small set of current-state samples (prints, removable media process, backup labeling approach) to see gaps. ¹

Near-term (after the initial baseline exists)

• Publish the Media Marking Standard with examples and an exception process. ¹
• Update workflows: print templates, removable media issuance tickets, backup labeling/inventory steps, device lifecycle checklists. ¹
• Train the roles that touch media and add quick-reference job aids near printers and in ticket templates. ¹

Ongoing (operate and prove)

• Run periodic spot checks and record findings and fixes. ¹
• Review third-party touchpoints (shredding services, IT disposal, offsite storage) and confirm contracts and procedures reflect your marking/handling rules. ¹
• Keep an assessment-ready evidence folder in Daydream (or your GRC repository) that is refreshed on a recurring cadence. ¹

Frequently Asked Questions

Does 03.08.04 require marking every single page that contains CUI?

NIST SP 800-171 Rev. 3 states a media marking requirement but does not prescribe a single page-level method in the provided excerpt. Set a clear internal standard (for example, cover sheet plus page banners) and apply it consistently across your CUI paper workflows. ¹

How should we mark digital files that contain CUI?

Treat “marking” as unambiguous identification that a file contains CUI, such as standardized headers/footers in exported documents, naming conventions, or embedded classification metadata your tools can display. Document your chosen method and show examples from real repositories. ¹

Are backups considered “media” for this requirement?

Yes in practical assessment terms, because backups store CUI and can be moved, restored, or exported. Your evidence should show how backup sets that include CUI are identified and controlled through inventory, labels, or system tags. ¹

We prohibit USB drives. Do we still need a media marking control?

Yes, because paper, portable endpoints, and backups still exist as media paths in many environments. Document the prohibition as part of your scope and then implement marking for the remaining media types that can contain CUI. ¹

What if a third party prints or stores CUI for us?

Flow down handling expectations contractually and operationally, and require the third party to follow your marking standard or an equivalent documented standard. Retain evidence of requirements communicated and the third party’s procedure or samples. ¹

What evidence is “good enough” to prove marking is operating?

Provide a combination of: the approved standard, workflow artifacts (templates, ticket fields), inventories, and a small set of real samples (photos/scans/screenshots) plus a record of periodic checks. Auditors want to see repeatability, not one-off examples. ¹

Footnotes

1. NIST SP 800-171 Rev. 3