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VAST-4.4-adcom-extension-unknown-signal

VAST-4.4-adcom-extension-unknown-signal

<Extension ext="adcom"> type is not plcmt, pos, playbackmethod or attr

WarningCTV Ad PortfolioIAB CTV Ad Portfolio §Purpose of VAST extAll VAST versions

Short answer

The CTV Ad Portfolio round-trips exactly four AdCOM signals into VAST <Extensions> so that stitchers and measurement vendors downstream of the RTB transaction can validate the creative experience without the bid object. Those four are plcmt, pos, playbackmethod and attr. An Extension marked ext="adcom" with any other type will be ignored by conforming consumers.

Why this matters in production

This rule is a strong risk signal. Tags with this issue often still parse, but they become brittle across SDKs, SSAI resolvers, and CTV environments. 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

<Extension type="loudness" ext="adcom">
  <attr>21</attr>
</Extension>

Valid

<Extension type="attr" ext="adcom">
  <attr>21</attr>
</Extension>
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Other CTV Ad Portfolio rules

VAST-4.4-version-attributeDocument declares VAST 4.4, a working-group draft rather than a published specVAST-4.4-nonlinear-no-renderable-asset<NonLinear> has a SIMID interactive file but no renderable fallback assetVAST-4.4-nonlinear-mediafiles-empty<NonLinear> <MediaFiles> contains no renderable or interactive assetVAST-4.4-nonlinear-simid-iframe<IFrameResource apiFramework="SIMID"> is superseded by <InteractiveCreativeFile> in NonLinearVAST-4.4-nonlinear-video-no-duration<NonLinear> delivers video but has no <Duration>: quartile tracking cannot fireVAST-4.4-adcom-extension-type-mismatch<Extension> type attribute and AdCOM payload element name disagreeVAST-4.4-adcom-signal-not-integerAdCOM signal payload in <Extension> is not an integerVAST-4.4-adcom-plcmt-valueAdCOM plcmt outside the Plcmt Subtypes (Video) range 1–9