Pre-fetch tags

Pre-fetch tags request ads from the DART ad server without logging impressions at the time of the request. They're used to deliver Rich Media Flash-in-Flash creatives and In-Stream video creatives. With pre-fetch tags, impressions are logged only after the video has buffered enough to start playing.

Here's an example:;kw=[keyword];sz=widthxheight;ord=[timestamp];dcmt=text/xml

Anatomy of Pre-Fetch Tags

To get a better understanding of the pre-fetch tags, let's look at them part by part. These parameters are the same as in standard tags.

pfadx: Lets the ad server know that this is a pre-fetch (pf) tag and an ad command for XML (adx).;kw=[keyword];ord=[timestamp];: These parameters are the same as in standard tags.

sz=widthxheight: Dimensions of the placement, in pixels. (The value of the sz parameter is always 0x0 for VAST placements.)

dcmt=text/xml: MIME stands for Multipurpose Internet Mail Extensions, which tell the browser what type of content you're sending. In this case, the MIME type is text/xml, which means that the content being sent is text in the form of XML code.

How helpful is this article:

Feedback recorded. Thanks!
  • Not at all helpful
  • Not very helpful
  • Somewhat helpful
  • Very helpful
  • Extremely helpful