Here's an example from the Prebid.js documentation
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To have an ad in a SafeFrames, it's not just about changing the type of HTML tag. You'll need to include this SafeFrames library in your website.
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Fenced frames are a new HTML tag added since Chrome 115 in the context of the Privacy Sandbox. It prevents the publisher site from knowing which ad is being displayed in the fenced frame because it can't even read the fenced frame's source URL. More details.
Not widely supported by all browsers. Which browsers support it?
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