Documentation

How the preference centre shows features

The stock IAB preference centres in React, Next.js, Vue, Svelte, Astro and the script tag follow TCF 2.4 and Policies v5.0.b. Special purposes stay in their locked section with a lock icon, because the visitor cannot object to them.

Features get their own section after the special purposes. It shows the IAB standard text for features from the Global Vendor List's standardTexts.features. If the list has no standard text, it shows the iab.preferenceCenter.features.description translation. Each feature lists its name, description, illustrations and the vendors that use it. The section has no switch, lock or vendor toggle, because TCF forbids showing features next to a control that cannot be disabled.

The feature section follows the theme's spacing and typography tokens. Its disclosure arrows are decorative and stay out of the accessibility tree.

A custom preference UI gets the same rows from resolveIABDialogDisplayModel in @c15t/iab/headless. essentialRows holds the special purposes only. featureRows holds the features, with locked: false and toggle: 'none', so render them without a control. featuresStandardText is the standard text, or null when you should use the translation.

Each vendor's privacy policy and legitimate interest links come from its urls[] entry in the Global Vendor List. The stock preference centres pick the entry for the language the banner shows, then English. A custom UI gets the same links from resolveIABVendorUrls(vendor, language) in @c15t/iab/headless, or from policyUrl and legitimateInterestUrl on the vendors processGVLForDialog returns when you pass it language. Vendor lists older than GVL v3 have a single policyUrl field, which c15t still reads.

Consent scope

c15t stores TCF choices per site and browser, which the TCF calls service-specific scope. It does not sync TC strings across devices, and every TC string it writes has IsServiceSpecific set to 1.

Do not use /consent/check or your own account data to skip the TCF banner on another device. That turns the choice into multi-device scope, which the TCF requires you to disclose in the first layer, and c15t does not show that disclosure. The isServiceSpecific option is deprecated. c15t ignores it and logs a warning when you pass false.