Excluding or Targeting Unknown Values
In some cases, you may want to exclude or target auctions where a particular field is empty. For example, when the domain field is empty or the app bundle field is empty.
How to exclude/target Unknown values for non-list based targeting keys
For all targeting keys where there is a select menu for targeting values, there is an “Unknown” value in the targeting drop down. In these cases, simply select the “Unknown” option and select "Include" or "Exclude".
How to exclude/target Unknown values for list based targeting keys
There are several targeting keys that use lists, including domain lists, app bundle lists, Site ID lists and more. For all list type targeting keys, add a value of -1 to the list and then either exclude or include target that list according to your use case.