Detecting XDP tags used in a PDF form

I'm writing a program to automatically populate a PDF form. It does so by creating an XDP file.

I already know most of the xml tags to use in the XDP file, but there are some form elements in the PDF file I don't know the appropriate tag for. Is there an开发者_开发问答y way I can look at the PDF file to see what xml tags would correspond to those form elements? Or to just list the xml tags for all the form elements? I've tried looking at the PDF file itself, but it doesn't even contain the strings for the xml tags I know about.

Easy solution: Document → Forms → Export Data.