vastlint
VAST-3.0-icon-attrs

VAST icons need size and position attributes

Icon missing recommended attributes (program/width/height/position)

WarningAmbiguousIAB VAST 3.0 §2.4.5VAST 3.0, 4.0, 4.1, 4.2, and 4.3

Short answer

If your <Icon> is missing program, width, height, or xPosition and yPosition, players can render it inconsistently or ignore it entirely.

While `<Icon>` has some individually required attributes, the combination of `program`, `width`, `height`, and `xPosition`/`yPosition` together defines a complete, renderable icon. Missing any of these will produce unpredictable rendering.

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. Ambiguous rules matter because undefined behavior shifts between vendors. Fixing them reduces the chance that two standards-compliant systems interpret the same tag differently. Affected scope: VAST 3.0, 4.0, 4.1, 4.2, and 4.3.

How to fix

Add program, width, height, xPosition, and yPosition attributes to <Icon> for reliable rendering across all players.

Invalid

<Icon duration="00:00:05" offset="00:00:10">
  <StaticResource creativeType="image/png">
    <![CDATA[https://cdn.example.com/adchoices.png]]>
  </StaticResource>
</Icon>

Valid

<Icon program="AdChoices" width="50" height="20" xPosition="right" yPosition="top" duration="00:00:05" offset="00:00:10">
  <StaticResource creativeType="image/png">
    <![CDATA[https://cdn.example.com/adchoices.png]]>
  </StaticResource>
</Icon>
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Other Ambiguous rules

VAST-3.0-progress-offset<Tracking event="progress"> requires an offset attributeVAST-2.0-nonlinear-dimensions<NonLinear> missing required width or height attributesVAST-2.0-companion-dimensions<Companion> missing width or heightVAST-4.0-wrapper-clickthrough<ClickThrough> inside Wrapper <VideoClicks> was removed in VAST 4.0 (re-allowed in 4.2)VAST-4.2-icon-fallback-image-width-height<IconClickFallbackImage> should have width and height attributesVAST-2.0-linear-tracking-quartiles<Linear> has no standard quartile tracking events — measurement system receives no signal