I started trying to implement drag-and-drop of virtual files (from a C# 4/WPF app) with this codeproject tutorial. After spending some time trying to figure out a DV_E_FORMATETC error, I figured out I need to support the "Shell IDList Array" data format. But there seems to be next to zero documentation on what this format actually does.
After some searching, I found this page on advanced data transfer which said that a Shell IDList Array was a pointer to …