ISM-1216 ASD Information Security Manual (ISM)

Ensure Correct Labelling of Non-conformant Cables

Non-standard cable colours for SECRET and TOP SECRET must be labelled correctly at inspection points.

Preventative SECRET TOP SECRET ASD Information Security Manual Guidelines for communications infrastructure Labelling Cabling security

🏛️ Framework

ASD Information Security Manual (ISM)

🧭 Control effect

Preventative

🔐 Classifications

S, TS

🗓️ ISM last updated

May 2024

✏️ Control Stack last updated

22 Feb 2026

🎯 E8 maturity levels

N/A

Guideline

Guidelines for communications infrastructure

Section

Cabling infrastructure

Topic

Cable Colour Non-conformance

Official control statement

SECRET and TOP SECRET cables with non-conformant cable colouring are banded with the appropriate colour and labelled at inspection points.

Source: ASD Information Security Manual (ISM)

Plain language

This control is about making sure cables that carry top secret information are marked correctly if they don't follow standard colour rules. This is important because if these cables aren't marked, someone could accidentally tap into or mishandle sensitive information, leading to security breaches or data leaks.

Why it matters

If non-conformant SECRET/TOP SECRET cable colouring isn’t correctly banded and labelled at inspection points, cables may be misidentified, increasing exposure risk.

Operational notes

At defined inspection points, verify each non-conformant SECRET/TOP SECRET cable has the correct colour banding and clear label; replace missing/incorrect bands immediately.

Implementation tips

IT team should identify cables carrying SECRET and TOP SECRET information within the organisation. They can do this by reviewing the documentation of the existing cabling infrastructure to know which cables are meant for high-level secret data.
Facilities manager should ensure that non-standard coloured cables are clearly marked with the prescribed band colours. They can achieve this by using banding materials that are visible and consistent with the specified standards.
The IT security officer should set up regular inspection points for cable checks. This involves scheduling periodic visual inspections where cables are examined to ensure all are properly labelled and marked at accessible points.
Office manager should maintain an inventory record of all cables used for sensitive information. This record should detail the location, type, and banding status of the cables and be updated after each inspection.
Training coordinator should organise workshops to educate staff on the importance of non-standard cable marking for secret information. They can do this by inviting a cyber security expert to explain the risks associated with improper cable handling.

Audit / evidence tips

Ask: the cable inventory list

Good: includes a complete list with all non-standard coloured cables properly documented with their inspection points noted
Good: shows regular inspections with corrective actions taken as needed
Ask: to see photographs or samples of the marked cables

Good: includes evidence that the banding is bright and easily identifiable
Good: includes attendance records showing sessions were conducted with relevant staff in attendance
Ask: a policy document on cable handling procedures

Good: includes a clear policy document with steps and responsibilities outlined for cable management and markings

Cross-framework mappings

How ISM-1216 relates to controls across ISO/IEC 27001, Essential Eight, and ASD ISM.

These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.

ISO 27001

Control	Notes	Details
Partially meets (1)
Annex A 5.13	ISM-1216 requires SECRET and TOP SECRET cables that do not use conformant colouring to be banded with the correct colour and labelled at ...