NIST SP 800-53 Rev. 5 MP-3 — Media Marking

What this control requires

Mark system media with distribution limitations, handling caveats, and security markings. Exempt certain media from marking if in controlled areas, ensuring proper identification and protection. This control supports the Media Marking capability within the Media Protection family.

In plain English

Mark system media with distribution limitations, handling caveats, and security markings. In practice, this means you can prove you policy management-level controls on a defined cadence.

Why it matters

SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan.

Within Media Protection, the assessor will trace your implementation back to the catalogue reference (Control MP-3) and look for objective evidence on the latest two assessment cycles.

How to implement

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Policy. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• System. Document the trigger, the owner and the cadence.
• Control. Document the trigger, the owner and the cadence.
• Scope: management, system, protection, capability, media, mark, identification, policy.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.

Signed policy or standard documents the safeguard. Focus: Media Marking.

Common pitfalls

• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• NIST SP 800-171 Rev. 3 3.8.4 — Media Marking
• HIPAA (45 CFR Part 164) 164.310(d)(1) — Device and Media Controls
• BSI C5:2020 SP-01 — Documentation, communication and provision of policies and instructions
• ISO/IEC 27001:2022 A.7.14 — Secure disposal or re-use of equipment
• SOC 2 (2017 TSC) C1.1 — Confidential Information Identification and Maintenance

Related controls in NIST SP 800-53 Rev. 5

• Control MP-8 — Media Downgrading
• Control PL-6 — Security-Related Activity Planning
• Control MP-8(3) — Controlled Unclassified Information
• Control MP-8(4) — Classified Information
• Control MP-6(5) — Classified Information
• Control MP-6(6) — Media Destruction

References

• NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5
• Catalogue identifier: Control MP-3

Topics: governance riskpolicy management