Yes, you can include one target list inside another list. This would be important if you have a set of criteria that you want to include in multiple target lists. For example a target list that includes all North American Valid contacts, or a suppression list of all competitors.  Your options would be to add all the criteria on these sub lists (For example all North American Valid contacts) and then add your additional criteria for the list you want to create. Or the easier solution is to utilize the Existing Target List criteria inside your Target list. That way if the criteria on one or your sub lists change you only need to change it in one place. For example if you need to add a competitor and you had that data in a sub list you would only need to change one list vs. many. This will also make the Target definition of your list shorter and easier to manage.

To use this feature you will want to start by creating your sub lists in a separate folder to help make your tracking of the lists easier. We recommend a folder title of System Target Lists or Sub Lists. The existing target list that is used inside of another target list can be stored in any file we just recommend storing them together to make maintenance easier. To utilize any of these lists choose Existing Target In the Criteria Type Definition drop down and then select the sub list to include.

On the Target Summary Screen you can see with other target list(s) are using the sub list.