[en] Market Coupling is both a mechanism for matching orders on the exchange and an implicit cross-border capacity allocation mechanism. Market Coupling improves the economic surplus of the coupled markets: the highest purchase orders and the lowest sale orders of the coupled power exchanges are matched, regardless of the area where they have been submitted; matching results depend however on the Available Transfer Capacity (ATC) between the coupled hubs. Market prices and schedules of the day-ahead power exchanges of the several connected markets are simultaneously determined with the use of the Available Transfer Capacity defined by the relevant Transmission System Operators. The transmission capacity is thereby implicitly auctioned and the implicit cost of the transmission capacity from one market to the other is the price difference between the two markets. In particular, if the transmission capacity between two markets is not fully used, there is no price difference between the markets and the implicit cost of the transmission capacity is null. Market coupling relies on the principle that the market with the lowest price exports electricity to the market with the highest price. Two situations may appear: either the Available Transfer Capacity (ATC) is large enough and the prices of both markets are equalized (price convergence), or the ATC is too small and the prices cannot be equalized. The Market Coupling algorithm takes as an input: 1 - The Available Transfer Capacity (ATC) between each area for each flow direction and each Settlement Period of the following day (i.e. for each hour of following day); 2 - The (Block Free) Net Export Curves (NEC) of each market for each hour of the following day, i.e., the difference between the total quantity of Divisible Hourly Bids and the total quantity of Divisible Hourly Offers for each price level. The NEC reflects a market's import or export volume sensitivity to price. 3 - The Block Orders submitted by the participants in each local market. The Market Coupling algorithm provides as an output for each market: The set of accepted Block Orders; The Net Position for each Settlement Period of the following day; and The price (MCP) for each Settlement Period of the following day. The results of the Market Coupling algorithm are consistent with a number of 'High Level Properties'. The High Level Properties can be divided into two subsets: Market Coupling High Level Properties (constraints that the Market Results fulfill for each Settlement Period), and Exchanges High Level Properties (constraints that the Market Results must fulfill for each Settlement Period. They reflect the requirements of individual participants trading on the exchanges). Using the ATCs and NECs, the Market Coupling algorithm can determine for each Settlement Period the Price and Net Position of each market. A NEC is built for a given set of accepted Block Orders (Winning Subset). When a set of NECs is used to determine the prices and Net Positions of each market, the set of prices returned for each market may very well not be compatible with this assumed Winning Subset. The Winning Subset needs to be updated and the calculations run again with the derived new NEC. This procedure must be repeated until a stable solution is found. As a consequence, the Market Coupling algorithm involves iterations between two modules: The Coordination Module which is in charge of the centralized computations; The Block Selector of each exchange which performs the decentralized computations. The iterative nature of the algorithm derives from the treatment of Block Orders. The data flows and calculations of the iterative algorithm are described in the rest of the document