How can you require an attachment as part of the new item request workflow?

In Item Management "Definition Workflow Details" it appears "Attachments" is an LOV for Business Entity. I'm assuming this would allow you to require attachments to be mandatory to provide as part of the new item request workflow, but there's a dependent value column named "Associated Entity." Do you know where that's controlled at?

What I really want to know how to do is require an attachment as part of the new item request workflow.