For any data item, we list required and recommended properties. These are derived from Google’s recommendations and Schema App recommendations. The other properties do not have to be filled in, however we recommend you review them to see if they can be used to represent other information on the page. In addition to using the required and recommended properties to guide your schema markup, you can also use them to inform the information you could put on your page. Here’s our tutorial video on how to optimize an Organization. Learn more here. You may also get some guidance from our Ultimate Guide for Local Business Markup, since Local Business is a more specific type of Organization.