HoDoKu Sue De Coq

Greens  : {1}
Fins    : {2}
Endofins: {3}
Reds    : {0}
I'm sorry, I don't understand Sue De Coq, so I can't explain this hint.

Here's hobiwans explanation http://hodoku.sourceforge.net/en/tech_misc.php

The basic variant is rather simple: Look for cells at the intersection of a line (a row or a col) and a box. You have to find either two cells containing 4 candidates or three cells containing 5 candidates. Now find a bivalue cell in the line outside of the intersection whose candidates are drawn entirely from the intersection candidates. Find another bivalue cell in the box with candidates drawn from the intersection too, but different from the candidates in the line cell.

This constellation is a Sue de Coq: You can eliminate all line cell candidates from the rest of the cells in the line, all box cell candidates from the rest of the cells in the box and any intersection candidate that is left from both the line and the box. This can amount in some rather impressive eliminations.

Sue de Coq can be enhanced in two possible ways:

It's important to note, that an SDC can have only two cells in the intersection with the possible third cell being part of either the line or the box cells. Likewise, if additional candidates are used, that are not drawn from the intersection set, the same candidate can be used in line cells and box cells.