["name", "email", "mailing_address", "photo"]
Indicates the data to include when automatically populating the contacts in the textarea. When
name is included, then both the name and the email address are set in the textarea in the format
name <email>. When
name is not included, then only the email addresses are set and no additionally formatting is applied. When
mailing_address is included in the array, these will be included with the JSON data passed into the callback methods example.
See here for the format of the contacts array.