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From Sudopedia

Here is an extended form of the 2 string kite that can give up to two additional cell eliminations. The basic 2 string kite consists of 2 single link color chains at right angles with peer cells in a box. When I find this pattern, I look for a third color chain with one or two links, where one cell of this chain is a peer of one of the non=peer cells of the 2 string kite. If the third color chain has two links the peer cell is the center cell in the chain. To illustrate this consider the example in the article. If there is an X conjugate pair in r4c7 and r4c5. Then whenever r1c7 is X, the peer cell r4c7 is not X, and its conjugate r4c5 is X. This means that X cannot be in r7c5. Similiarly, if r4c7 and r6c9 are also conjugate pairs. then r7c9 can also be eliminated. When you find a 2 string kite and there is already a number in the single elimination cell, you may still be able to use this technique for cell eliminations. To a lesser extent, I have also used this extended technique with the empty rectangle technique. Nienhaus 7-19-08.

Let's assume that we have two strong conjugate pairs (d1 and d2) of the number n, which have one end in common group (row, collumn or block, but not the same cell!). Let's mark A the set of cells, which is seen by the second end of d1 and B the set of cells, which is seen by the second end of d2. If there are the cells in the intersection of A and B, which includes the number n as candidate, we cann delete n from these cells. This algorithm generalizes several methods – for example X-Wing, Skyskraper, Sashimi X-Wing, Turbot Fish, 2-String Kite, Guardians, Double Guardians and so on.

We can still extend this method. Let's assume, that we have the cycle of k of strong conjugate pairs (d1, d2, …, dk) of the number n. Then the same predicate as above is valid for the endpoints of cycle. [See this link: http://www.volny.cz/jiven/Kap323.htm] --Jiven 15:41, 10 November 2008 (CET)