VAST macros / Identity and privacy
[IFA] VAST macro
Short answer: The device advertising identifier (IDFA, AAID, or CTV ad ID) for the request. Introduced in VAST 4.1.
What it means
Resolves to the resettable device advertising identifier used for frequency capping and attribution: IDFA on iOS/tvOS, AAID on Android, or a platform-specific identifier on connected TV. Empty when the user has opted out.
Example value
After the player substitutes the macro, [IFA] becomes something like:
38400000-8cf0-11bd-b23e-10b96e40000dWhere it is valid
Impression, tracking, and click URLs that need a device identifier.
Macros are case-sensitive and substituted only inside URL fields. A macro written in the wrong case, or placed where it has no defined value, is sent to the server as literal text instead of a value.
Using it in a tag
<Impression><![CDATA[https://t.example.com/i?val=[IFA]&cb=[CACHEBUSTING]]]></Impression>VAST XML fragment only. This excerpt belongs inside a complete VAST document, so standalone validation will fail until it is wrapped in a full <VAST>response.
Related vastlint rules
- VAST-2.0-macro-unknown: URL contains a [MACRO] that is not a recognised IAB VAST macro
- VAST-2.0-macro-lowercase: Recognised macro is not uppercase — players match macro names case-sensitively
Related macros
- [IFATYPE]: The type of advertising identifier carried in [IFA] (e.g. idfa, aaid, rida).
- [LIMITADTRACKING]: Whether the user has enabled limit ad tracking (1) or not (0).
- [REGULATIONS]: Active privacy regulations for the request (e.g. GDPR, COPPA, CCPA).
Validate your macros
vastlint flags unknown, mis-cased, deprecated, out-of-context, and unencoded macros in any tracking, click, error, impression, or media URL:
# CLI: exits non-zero on errors, ideal for pipelines
vastlint check creative.xmlUse the right tool for this failure
If you already have the resolved XML, run a pure spec check. If you only have a live tag URL, test that endpoint first. If the failure happens in the wrapper chain, inspect each hop.