How to teach Siri correct foreign name pronunciation?

With many foreign-language names in my Contacts, Siri gets most of them wrong. There is a time consuming, and not always successful, way to teach Siri via the microphone. It would be much easier for me if I could use the Phonetic and/or Pronunciation fields in Contacts to accomplish this.

To begin with, I'm not sure what's the difference, in this context, between the Phonetic and Pronunciation fields.

So far I've been filling in those fields with text on hit-or-miss trial basis. Are there specific ways that these fields should be filled in? Special characters, or rules?