Abstract: Information pertinent to an item or product may be organized (e.g., structured) as a property of the item or product. The property may be represented (e.g., stored) as property data in a data structure of the item or product. A property may have one or more properties of its own. In this manner, information pertinent to items, products, properties, or any suitable combination thereof may be structured with any level of sophistication or complexity. Accordingly, a data structure may be generated to contain one or more properties of an item or product, as well as to contain one or more properties of those properties. A “composite property” refers to such a data structure and may be indexed based on a value contained therein. The value may be used to identify the item or the product, for example, as an instance of a virtual product.