I don't know if this is possible, the instructions say it's possible to attach the drag and drop feature to custom forms and certain fields but doesn't mention custom fields.

When I try to drag a file into certain fields like memo, date or PO# the field will turn green indicating I can attach an item to that field. This however doesn't appear to work intuitively with custom fields, so I don't know if it's even possible or not.

I've tried making a few variations of custom fields such as free text, document and hyperlink but none of them seem to allow me to attach files to them and I can't see anything I should be setting in the File Drag and Drop setup section.