MP-3: Media Marking

The mp-3: media marking requirement means you must label system media so people can immediately tell how the information may be shared, how it must be handled, and what security markings apply. Operationalize it by defining marking rules by data classification, applying labels at creation and transfer points, and retaining evidence that markings are consistently applied and reviewed. ¹

Key takeaways:

• Markings must communicate distribution limits, handling caveats, and security markings for information on media. ¹
• Execution depends on where media is created, stored, exported, and disposed, not just a policy statement.
• Auditors look for repeatable procedures and proof: standards, samples, tooling configs, and training records.

MP-3 sits in the Media Protection family and targets a common failure mode: data leaves its “safe” system context and becomes hard to control. Once information is written to removable media, printed, exported to a file share, staged on backup media, or copied into a portable format, the receiving person needs an immediate, unambiguous signal about what they can do with it and what protections are required.

The mp-3: media marking requirement is straightforward in text but tricky in execution because “media” covers more than USB drives. It includes laptops prepared for shipment, external drives used for data transfers, printed output, backup tapes (if you still have them), and even virtual media artifacts such as ISO images or exported database dumps, depending on your environment. The control expectation is consistent: markings must reflect the information’s classification and required handling in a way that works in real operations, including third-party handoffs.

This page gives requirement-level implementation guidance you can hand to control owners. It focuses on deciding what must be marked, defining a workable marking standard, implementing it through procedures and tooling, and collecting evidence that will satisfy assessors.

Regulatory text

Requirement (excerpt): “Mark system media indicating the distribution limitations, handling caveats, and applicable security markings (if any) of the information; and” ¹

Operator interpretation:
You must ensure that any system media containing your information is labeled so a user (or third party) can tell:

1. Distribution limitations (who it may be shared with),
2. Handling caveats (how it must be protected), and
3. Applicable security markings (classification/marking schema your organization uses),
   based on what’s on the media. ¹

In practice, assessors expect two things:

• A defined marking standard tied to your data classification and sharing rules.
• Operational control that applies the standard at the points where media is created, copied, exported, stored, transported, and disposed.

Plain-English interpretation (what MP-3 is really asking)

MP-3 requires “instant context” for information off-system. A file name like final_report.pdf tells you nothing. A label like “CUI // Do Not Distribute Externally // Encrypt at Rest + In Transit” tells a handler what to do without hunting for a policy.

Media marking also reduces mistakes during:

• Incident response (people can quickly triage exposure and notification requirements).
• Third-party transfers (the recipient can apply correct protections).
• Physical security events (lost laptop/drive scenarios are handled faster because the sensitivity is clear).

Who it applies to

Entities:

• Federal information systems and contractor systems that handle federal data commonly adopt MP-3 as part of a NIST SP 800-53 program. ²

Operational contexts where MP-3 shows up:

• Removable media: USB drives, external SSDs/HDDs, SD cards.
• Printed media: reports, call logs, architecture diagrams, tickets printed for review.
• Backup and archival media: disk-based backups, long-term archives, offline replicas.
• Data transfer packages: database exports, log bundles, forensic images, customer deliverables.
• End-user devices as media: laptops or mobile devices issued for travel or shipped to staff (if they store sensitive data).
• Third-party workflows: data sent to a consultant, eDiscovery provider, managed service provider, or cloud support channel.

What you actually need to do (step-by-step)

Use this as a runbook for the control owner.

Step 1: Define what “media” means in your environment

Create a scoped inventory list of media types you will mark. Keep it practical:

• Physical removable devices
• Printed output
• Backup media and exported images
• High-risk file formats (CSV exports, PDF reports, database dumps)

Deliverable: Media Marking Scope (one pager) listing in-scope media types and out-of-scope rationale.

Step 2: Define your marking standard (the “label schema”)

Build a small set of markings tied to your data classification and sharing model. A common, auditable schema has:

• Classification / sensitivity (e.g., Public, Internal, Confidential, CUI, Secret as applicable)
• Distribution limitation (e.g., “Internal Only,” “Customer-Approved Recipients,” “No External Distribution”)
• Handling caveats (e.g., “Encrypt if portable,” “Store in approved container,” “Shred after use,” “Do not photograph”)

Deliverable: Media Marking Standard that includes:

• Marking text templates
• Color/format rules for physical labels
• Where labels must be placed (front page, spine, device casing)
• Exceptions (e.g., media too small to label, operational constraints)

Step 3: Map markings to data classification rules and owners

Tie the schema to your classification policy and decision rights:

• Who decides the classification for a new export?
• Who approves distribution changes?
• How do you handle mixed-content media (multiple classifications)?

A workable rule: mark to the highest sensitivity present on the media unless you can technically separate content.

Deliverable: RACI for media marking (data owner, system owner, IT, Security, Records Management).

Step 4: Implement marking at creation and transfer points

This is where most programs fail. Do not rely only on users “remembering.”

Cover at least these control points:

• Export workflows: add a required step in ticketing or change procedures for data exports to assign classification and apply label.
• Printing: configure secure print workflows where feasible; require cover sheets or headers/footers with classification and handling.
• Removable media issuance: require labeling before media leaves IT custody; record who received it and for what purpose.
• Backups/archives: apply markings to backup sets, containers, or the physical media; document how markings are maintained for rotated sets.
• Third-party transfers: require the package itself (encrypted container, folder banner, readme file) to carry the marking and handling instructions.

Deliverable: Media Marking Procedures integrated into operational SOPs (IT asset handling, data export SOP, print SOP, backup SOP).

Step 5: Add technical enforcement where possible

MP-3 is about marking, but you can strengthen reliability with tooling:

• Data loss prevention prompts or banners for exports
• File templates with required headers/footers
• Encryption tooling that forces a label selection before container creation
• Endpoint controls restricting removable media unless registered and labeled

Deliverable: Tool configuration evidence (screenshots, configuration exports, templates).

Step 6: Train the roles that touch media

Train for the job, not the policy:

• Help desk / desktop support (issuing devices, preparing removable media)
• Engineering and data teams (exports, logs, backups)
• Legal and HR (printing, case files)
• Anyone sending packages to third parties

Deliverable: Role-based training materials and completion records.

Step 7: Test and monitor (sampling beats promises)

Set a simple operating rhythm:

• Periodic sampling of labeled media (physical and digital packages)
• Review of export tickets to verify marking fields completed
• Exceptions log review (why something was not labeled and compensating controls)

Deliverable: Media marking QA log with samples, findings, and corrective actions.

Required evidence and artifacts to retain

Assessors typically ask for proof of design and operation. Maintain:

• Media Marking Standard (current, approved)
• Media Marking Scope statement
• Procedures/SOPs for exports, printing, removable media, backups
• Examples of markings:
  • Photos of labeled drives and storage cases
  • Redacted screenshots of labeled encrypted containers or deliverable folders
  • Sample printed documents showing headers/footers
• Training records for in-scope roles
• Exception register (with approvals and compensating controls)
• Sampling/QA results and remediation tickets

Daydream fit: many teams fail MP-3 on “evidence sprawl.” Daydream helps you map MP-3 to a control owner, documented procedure, and recurring evidence artifacts so audits don’t turn into screenshot hunts. ¹

Common exam/audit questions and hangups

Expect these questions, and prepare the artifacts above to answer them quickly:

1. “Show me your marking standard.”
   They want the schema and rules, not a paragraph in a policy.

2. “What media is in scope?”
   If you cannot define media types, you cannot prove coverage.

3. “How do you handle exports and ad hoc data pulls?”
   Auditors often target data extracts because they leave systems frequently.

4. “Show evidence markings are applied consistently.”
   Bring samples across teams and media types, plus your sampling log.

5. “What about third parties?”
   You need a packaging/transfer standard that includes markings and handling caveats.

Frequent implementation mistakes (and how to avoid them)

Mistake 1: Treating MP-3 as a “label printer project.”
Fix: start with classification-to-marking rules and apply them to workflows first; labels come last.

Mistake 2: Marking only physical devices, ignoring digital transfer packages.
Fix: require a label banner file (e.g., READ_ME_HANDLING.txt) plus folder naming conventions and encrypted container naming standards.

Mistake 3: No rule for mixed data.
Fix: default to highest sensitivity or enforce separation by design.

Mistake 4: Exceptions become the norm.
Fix: require time-bound exceptions with documented compensating controls (encryption, restricted access, logged transfer, return/destruction confirmation).

Mistake 5: No operating evidence.
Fix: set a lightweight sampling process and retain the results.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for MP-3. Treat MP-3 as an assessment-readiness and loss-prevention control: weak media marking increases the chance of improper sharing, mishandling by third parties, and delayed incident triage because nobody can quickly determine sensitivity. ¹

Practical 30/60/90-day execution plan

Use these phases to move from policy to operating control without guessing timelines.

First 30 days (foundation)

• Assign a control owner and approver for the Media Marking Standard.
• Define in-scope media types and key workflows (exports, printing, removable media, backups, third-party transfers).
• Publish the marking schema and templates (physical label formats, document headers/footers, “handling readme” template).
• Start collecting example artifacts (even if from a pilot group).

Next 60 days (operationalization)

• Embed marking steps into tickets/SOPs for exports and third-party transfers.
• Roll out physical label process for removable media issuance and returns.
• Update print guidance (cover sheets or required document headers/footers for sensitive prints).
• Train the roles that actually generate and move media.
• Stand up an exceptions log with approvals.

By 90 days (assurance)

• Implement sampling and QA checks across at least a few teams and media types.
• Close gaps found in sampling (unclear labels, inconsistent application, missing procedures).
• Package audit-ready evidence: standards, SOPs, training records, sample markings, exceptions, QA log.
• In Daydream, map MP-3 to the owner, procedure, and recurring evidence artifacts so the control stays “alive” between audits. ¹

Frequently Asked Questions

What counts as “system media” for MP-3?

Treat any medium that stores or carries your information as in scope, including removable drives, printed output, backups, and exported data packages. Define the list explicitly in a scope statement so teams apply markings consistently. ¹

Do we have to label every individual file?

MP-3 focuses on marking media; in practice you can mark at the container level (encrypted archive, folder, printed packet, drive label) if it clearly communicates distribution limits and handling caveats. If files are routinely separated from containers, add file-level headers/footers for the highest-risk document types.

How do we mark media that is too small to label, like some USB devices?

Use a labeled case, tag, or tamper-evident bag, and reference the device identifier in your issuance log. Document the exception method in the marking standard and require encryption plus custody tracking.

What should we do for third-party transfers?

Require a marked package (folder banner or readme with distribution/handling), encrypted transport when appropriate, and documented recipient authorization. Keep transfer records so you can prove markings and conditions were communicated.

How do we handle backups that rotate and get overwritten?

Mark the backup container, set, or physical media consistently and document how the marking persists across rotations (for example, labeling the cartridge or the storage case and maintaining an inventory). Your evidence should show the rule and samples of labeled backup media.

What evidence is most persuasive in an audit?

A written marking standard plus real samples across media types, supported by operating logs (issuance/transfer records, exceptions, and periodic QA results). Tool configuration exports and templates help show repeatability.

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5