VAST-4.4-version-attribute
Document declares VAST 4.4, a working-group draft rather than a published spec
Short answer
vast_4.4.xsd landed in the IAB VAST repository on 2026-07-17 alongside the CTV Ad Portfolio work, and its own annotation reads "DRAFT for working group discussion". There is no VAST 4.4 press release and no entry in IAB's release notes. Every CTV Ad Portfolio example IAB publishes declares version="4.2". Declaring 4.4 in production risks players that version-gate strictly rejecting the tag, and buys nothing: the new NonLinear content model is accepted on 4.2 and 4.3 too.
Why this matters in production
This rule is advisory rather than fatal, but it still matters for portability, debugging speed, and keeping tags predictable across different buyers and playback stacks. The CTV Ad Portfolio standardises Pause, Screensaver, Overlay, Squeezeback and In-Scene ads, which ran for years on bespoke per-publisher integrations. These rules cover the VAST side of that contract: the NonLinear MediaFiles delivery model, the AdCOM signals round-tripped into Extensions so stitchers can validate the experience without the bid object, and the QR code block. The signaling guidance is final; the VAST 4.4 schema that accompanies it is still a working-group draft, so anything sourced only from the schema is reported as a warning or a note. Affected scope: All VAST versions.
Invalid
<VAST version="4.4">Valid
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