Swordfish

Swordfish is a three-way version of X-Wing. How it got the nautical name, I don’t really know!

Look for three columns with only two or three candidates for a given digit. If these fall on exactly three common rows, and each of those rows has at least two candidate cells, then all three rows can be cleared of that digit - except in the defining cells.

Rows and columns can be swapped in the above description of course.

At this point, after performing candidate reduction using other techniques, we have a swordfish in the 1s. The green-marked cells are the only cells in columns one, four and six that can contain a 1, and because each of those columns must only contain one 1, and since the cells also share three common rows, the cells are linked in a similar manner to the X-wings. The net effect is that we can eliminate 1 from the candidates of the other cells in rows two, six and nine. The blue circles show two 1s we can eliminate.