Rules and ethics
Part of Privacy first measurement rules: five decisions before you launch
Four connected disclosures every measurement operation should publish
Write a measurement disclosure policy that separates privacy information, device choices, advertising labels, evidence limits, interests and corrections.
A privacy first measurement disclosure policy should tell different readers different things at the moment each fact matters. One long privacy notice cannot also serve as a device-permission explanation, advertising label, research method, conflict statement and correction log.
This method is intended for an organisation operating in England. The cited privacy and consumer sources apply across the UK, while CAP advice concerns communications within its remit. Material was reviewed on 5 September 2026. No notice or campaign was user-tested, and qualified legal review remains necessary.
What to take away
- Publish four connected disclosures with the same data-flow owner and version number.
- Each disclosure serves a different reader at the moment the fact matters.
- A disclosure register should record evidence, system, review and next review trigger.
- Corrections must be visible and preserve the trail of what changed and why.
- Any mismatch between policy and live system is a stop condition before release.
Build four connected disclosures
Create four records with the same data-flow owner and version number.
Four Connected Disclosures
- Privacy information
- Device storage or access information
- Advertising labels
- Evidence limits and corrections
Privacy information
Explain which personal information is collected or derived, the purposes and lawful bases, recipients, retention, rights and contact route. The ICO's right-to-be-informed guidance says privacy information must be concise, transparent, intelligible and accessible. It also supports layered and just-in-time techniques.
Do not describe modelled audiences as raw observations or hide a new advertising purpose beneath "service improvement". Bring relevant changes to people's attention before the new processing where required.
Device storage or access information
At the choice point, identify the purposes and material parties behind cookies, pixels, SDKs, tags or similar techniques. State how a person consents, objects or withdraws, according to the applicable route. The ICO's storage and access guidance separates PECR requirements from related UK GDPR processing.
A "first-party" badge, server-side deployment or product privacy setting does not decide whether the operation is exempt. The text and interface must match tested network behaviour.
Advertising and commercial-interest labels
Mark promotional material before people engage when the commercial character is not obvious. The CAP Code recognition rules require marketing communications to be identifiable and advertorials to be clear. A footer that reveals sponsorship after the claim may arrive too late.
State payment, commission, ownership, free access, gifts and editorial control where they affect a review or endorsement. The CMA's reviews and endorsements collection explains the 2025 consumer-law changes, including the banned practice concerning fake and concealed incentivised reviews.
Measurement-method note
Place a short method beside reported results. It should name the population, period, unit, denominator, exclusions, attribution window, matching rules and material uncertainty. Label observed, imported, attributed and modelled values separately. Say whether the work involved hands-on testing, desk research or neither.
If the organisation compares suppliers, publish common criteria, evidence date and exclusions. If it recommends a provider, disclose relevant commercial relationships. These statements support informed interpretation; they do not replace privacy or advertising notices.
Assign an owner to each statement
Maintain a disclosure register with these fields:
| Field | Required entry |
|---|
Disclosure Register Fields
- Claim or data use
- Audience and placement
- Evidence owner
- System owner
- Legal or code review
- Next review trigger
The evidence owner should be able to reproduce every published result. The system owner should demonstrate refusal, withdrawal and deletion behaviour. The advertising reviewer should see the whole presentation, not isolated sentences.
Publish corrections without erasing the trail
Give readers a visible route to report a problem. Record what changed, why, when and which outputs were affected. If an earlier figure relied on the wrong denominator or an undisclosed model, correct both the result and its interpretation.
Before release, compare the policy with the live system, supplier terms and campaign copy. Any mismatch is a stop condition. Approval should be version-specific and should not claim that future operation is guaranteed compliant.
Before you act
- Create four records with the same owner and version.
- State purposes and parties at the choice point.
- Mark promotional material before people engage.
- Place a short method beside reported results.
- Maintain a disclosure register with required fields.
- Compare policy with live system, supplier terms and campaign copy.
Common questions
What four disclosures should a measurement operation publish?
Privacy information, device storage or access information, advertising and commercial-interest labels, and a measurement-method note. Each record should share the same data-flow owner and version number, and each serves a different reader at the moment the fact matters.
What should a disclosure register contain?
Fields for claim or data use, audience and placement, evidence owner, system owner, legal or code review, and next review trigger. The evidence owner must reproduce every published result, the system owner must demonstrate refusal, withdrawal and deletion behaviour, and the advertising reviewer must see the whole presentation.
How should corrections be handled?
Give readers a visible route to report a problem. Record what changed, why, when and which outputs were affected. If an earlier figure relied on the wrong denominator or an undisclosed model, correct both the result and its interpretation. Approval should be version-specific.
