Can someone please explain to me how the new mapping of PDF properties in PDM Pro 2016 works.

In the what's new document it talks about the PDF plug-in, do I need to install that?

We currently use 'Description' as the title of our documents. I see that PDF's use 'title' as a custom property if I input the document name into 'Title in the PDF file how can I map that to 'Description'.

I guess I really don't understand how custom properties and mapping is supposed to work with PDF files.

Thanks,