practices. First, it must be established whether the accused undertaking has a dominant position in the tying or tied product market. Subsequently, the next step is to determine whether the dominant undertaking tied two distinct products. This is important as two identical products cannot be considered tied under Article 102(2)(d) formulation that states products will be considered tied if they have no connects ‘by their nature or commercial usage’. This arises problems in the legal definition of what will amount to tying in scenarios of selling cars with tires or selling a car with a radio. Hence, the Commission provides guidance on this issue by citing the judgement in Microsoft and states that "two products are distinct if, in the absence of tying or bundling, a substantial number of customers would purchase or would have purchased the tying product without also buying the tied product from the same supplier, thereby allowing stand-alone production for both the tying and the tied product". Next issue is whether the customer was coerced to purchase both the tying and the tied products as Article 102(2)(d) suggests: ‘making the conclusion of contracts subject to acceptance by the other parties of supplementary obligations’. In situations of contractual stipulation, it is clear that the test will be satisfied; for an example of a non-contractual tying see Microsoft. Furthermore, for an undertaking to be deemed anti-competitive is whether the tie is capable of having foreclosure effect. Some examples of tying practices having an anti-competitive foreclosure effect in case law are the IBM, Eurofix-Bauco v Hilti, Telemarketing v CLT, British Sugar and Microsoft. Subsequently, the defence available for the dominant undertaking is that it can provide that tying is objectively justified or enhances efficiency and the commission is willing to consider claims that are tying may result in economic efficiency in production or distribution that will bring benefit to the consumers. See also Complementary good Iunctim Loss leader The OSx86 Project or 'Hackintosh', breaking the tie Apple holds between its hardware and Mac OS X to run the operating system on non-Apple hardware. Product bundling Product churning Vendor lock-in Digital rights management Tying of the iPhone to AT&T References Bibliography Donald Turner, Tying Arrangements Under the Antitrust Laws, 72 Harv. L. Rev. 50 (1958); George J. Stigler, A Note On Block Booking, 1963 Supreme Court Review 152; Kenneth Dam, Fortner Enterprises v. United States Steel: Neither a Borrower Nor