ASD ISM 0201 Labelling requirements for TOP SECRET conduits
What it says
Labels for TOP SECRET conduits are a minimum size of 2.5 cm x 1 cm, attached at five-metre intervals and marked as 'TS RUN'.
Quoted as published. Everything else on this page is written by Control Stack.
What it means
In plain EnglishTOP SECRET conduits must have labels every 5 metres, marked 'TS RUN', and be at least 2.5 cm by 1 cm in size.
This control is about making sure that the infrastructure used to carry highly sensitive information is clearly labelled. If these labels are not present, someone might accidentally damage the conduits or connect unauthorised devices, leading to leaks of top-secret information which could significantly harm national security or an organisation's operations.
Free. Save your status, tasks and notes.
Why it matters
Missing 2.5 cm x 1 cm 'TS RUN' labels at 5 m intervals increases the chance TOP SECRET conduits are misidentified or mishandled, risking compromise of TOP SECRET data.
How to implement
The facilities manager should ensure that all conduits designated for carrying top-secret communications are labelled correctly.
Arrange for labels to be ordered through a trusted security supplier, ensuring the labels meet the required size and content specifications.
The IT infrastructure team should be responsible for physically attaching the labels to the conduits.
They should measure out five-metre intervals along each conduit and apply the labels marked 'TS RUN' to ensure visibility.
The security officer should periodically inspect conduits to verify labels are intact and clearly visible.
Use a checklist during walk-through inspections to ensure every five metres of the conduit is labelled as required.
The procurement team should document the purchase and acquisition of the labels.
Keep records of these purchases including supplier details and specifications of the labels to ensure compliance with security standards.
The IT oversight team should keep a maintenance log for conduit labelling.
Record the date of each inspection, any issues identified, and corrective action taken to maintain proper labelling.
Keep it running
Inspect TOP SECRET conduits to confirm 2.5 cm x 1 cm 'TS RUN' labels are present every five metres, legible, securely attached, and not covered or removed.
Evidence and audit
- Check 1 of 4What an auditor asks for
Ask for
The maintenance log of conduit labels: Request to see the documented records of label checks and any corrective actions taken.
Look at
Regular check entries and notes on condition or replacement of labels.
Good evidence
Record shows consistent checks at required intervals.
- Check 2 of 4What an auditor asks for
Ask for
The documentation of label purchases including specifications. Check for supplier details and compliance with size and content requirements.
Good evidence
Confirms labels meet the 2.5 cm x 1 cm size and 'TS RUN' marking.
- Check 3 of 4What an auditor asks for
Ask for
How they ensure conduits are properly labelled and maintained. Listen for details about the processes in place for regular checks and the handling of non-compliance.
Good evidence
Includes regular check procedures and past compliance actions.
- Check 4 of 4What an auditor asks for
Ask for
An IT or security staff member to demonstrate how they check conduit labelling. Observe the process and measures they take if a label is missing or damaged.
Good evidence
Demonstration shows adherence to the procedure and corrective steps.
Mappings
Closest match in ISO/IEC 27001: A.5.12, Information classification policy and practices, which this control partially meets.
ISO/IEC 27001: 2 mappings
This control partially meets A.5.12.
ISM-0201 mandates a specific handling safeguard for TOP SECRET environments by requiring conduits to be clearly identified as TOP SECRET runs. Annex A 5.12 establishes the broader requirement to classify information according to confidentiality, integrity and availability needs, which is what drives the existence of a TOP SECRET category and associated handling rules. ISM-0201 is therefore a concrete, classification-driven control that sits underneath the classification policy and practices required by Annex A 5.12.
This control partially meets A.5.13.
ISM-0201 requires very specific physical labelling of TOP SECRET conduits (minimum label size, five-metre intervals, and the marking 'TS RUN'). Annex A 5.13 requires an organisation to establish and implement procedures for labelling information in line with its classification scheme, which can include requirements for how classified assets and supporting infrastructure are marked. ISM-0201 is a highly prescriptive, TOP SECRET-specific implementation detail within the broader labelling governance envisaged by Annex A 5.13.
Mappings show how controls relate across frameworks. They do not imply full equivalence or certification.