An Actual Product or Service Instance is a single identifiable object or action that creates some increase in utility (in the economic sense) for the individual possessing or using this very object (Product) or for the individual in whose favor this very action is being taken (Service). Products or Services are types of goods in the economic sense. For an overview of goods and commodities in economics, see Milgate (1987). Examples: MyThinkpad T60, the pint of beer standing in front of me, my Volkswagen Golf, the haircut that I received or will be receiving at a given date and time. Note: In many cases, product or service instances are not explicitly exposed on the Web but only claimed to exist (i.e. existentially quantified). For a detailed discussion and practical solutions, see section 3.3.3 of the GoodRelations Technical Report.