VAST-4.1-companion-renderingmode-value
VAST-4.1-companion-renderingmode-value
Companion renderingMode must be default, end-card, or concurrent
WarningValuesIAB VAST 4.1 §2.4.2VAST 4.1, 4.2, and 4.3
Short answer
The renderingMode attribute on <Companion> (VAST 4.1+) must be default, end-card, or concurrent. Other values are not defined.
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. Value-format rules tend to fail at the moment a player interprets a field such as duration, skipoffset, bitrate, or versioning. They are especially painful because the XML can look valid at a glance. Affected scope: VAST 4.1, 4.2, and 4.3.
How to fix
Set renderingMode on <Companion> to default, end-card, or concurrent.
Check your VAST tag for
VAST-4.1-companion-renderingmode-value and other issues instantly.Validate a tag →Other Values rules
VAST-2.0-duration-format<Duration> value does not match HH:MM:SS[.mmm] formatVAST-2.0-mediafile-delivery-enum<MediaFile> delivery must be "progressive" or "streaming"VAST-3.0-skipoffset-formatLinear skipoffset does not match HH:MM:SS[.mmm] or n% formatVAST-3.0-progress-offset-formatTracking progress offset does not match required formatVAST-3.0-skip-event-no-skipoffsetskip tracking event present but Linear has no skipoffset attributeVAST-3.0-minmaxbitrate-pair<MediaFile> must have both minBitrate and maxBitrate or neitherVAST-3.0-bitrate-conflict<MediaFile> has both bitrate and minBitrate/maxBitrateVAST-4.0-tracking-event-removedfullscreen/exitFullscreen tracking events were removed in VAST 4.0