The following section describes what ads.txt is and how you should use this information.

What is ads.txt and app-ads.txt

Ads.txt and app-ads.txt are standards introduced some years ago by the IAB Tech Lab. They require publishers to list all of the companies who are authorized to sell their inventory in a specific format, at a specific location—for both websites (ads.txt) and applications (app-ads.txt). The objective of these standards are to reduce fraud by allowing buyers to identify those companies who are authorized to sell a publisher’s inventory. If a company is not on this list and is trying to sell a publisher’s inventory then it is likely fraudulent. It is a best practice to only buy from websites and apps that have an ads.txt or app-ads.txt file, and only from sellers who are authorized to sell it. For more information click here: https://iabtechlab.com/ads-txt/.

How is TAG TrustNet checking if websites and applications have these files?

TAG TrustNet has built its own web crawler to check if ads.txt files are present on websites, and is using a webcrawler from the IAB Tech Lab to check if app-ads.txt files are present on apps.

What does it mean if the TAG TrustNet report says there is no ads.txt or app-ads.txt file?

As indicated above, the IAB spec requires that these files must contain this authorized seller data in a specific format at a specific location. If the TAG TrustNet report says there is no ads.txt or app-ads.txt file it is likely it means one of the following:

• The file does not exist
• the domain or app that was provided in the DSP log file was invalid, and it is not possible to find the related ads.txt or app-ads.txt file (for example, comcast.tubitv or j00kdsgdsdk)
• The file is formatted incorrectly (according to the IAB specification).
• There is some other technical problem with it meeting the IAB specification.