How do I organize the documents in the attachments tab #3, part b: attachments selected, as far as what is the "lead" document and “subordinate” document(s)?

This can be done in two ways:

1. Select the document by clicking on the doc name, then click on the button on the top right corner of this window labeled “Set as Lead Document.”
2. You can also do this by right-clicking the document and vSet as Lead Document.”

There is no specific order required for documents following the “lead” document.