This is for when you are doing a search or find via a workflow step and you would normally get back a bunch of Documents/Document data in a what can be a massive xml variable.  The ID List variable is more concise and will store just the Document Ids in a repeating xml structure to facilitate a subsequent iterator loop.

They did this to try and reduce the size of variables in workflow as it is not common to need all the other Document node data when the goal is grab a set of documents and then act on them individually via a loop.  

In other words, a normal XML variable is fine for the job and this has limited usage and doesn’t seem to add any benefit to performance or processing speed so it is likely rarely used.

Wow, this is great! I just learned something new about how using the ID List variable can help streamline the process by reducing the size of XML variables. It’s good to know that this approach is designed to improve efficiency when working with a large set of documents. I’ll test this out later and let you know the results. Thanks for sharing this insight!

Cool! This worked perfectly and is also returning only the ID. Thank you, Scott! I really appreciate your help.