Google Local More Details Entry using KML File

I need someone to show me how to create a KML file that will include additional fields into a Google Local listing. For example, most standard KML files only include the business address, description, etc. However, I believe there is a way to add additional fields in the KML file, such as by using the ExtendedData parameter, to add field names and values into the business's google local listing. This information will show up under the "More details" section of the Google Local Listing.