RCCRBB Sashimi Finned Mutant Swordfish

In an RCCRBB Finned Mutant Swordfish as defined here, Column-1 or Column-2 must contain the Candidate twice in the Square where the fin Cell is located.

If one of these Cells is solved, i.e. contains an initial value or an induced value, this would still lead to potential eliminations. Again, these eliminations would only take place in the Square containing the fin Cell.

This solved Cell is called the sashimi Cell.

An RCCRBB Finned Mutant Swordfish with a sashimi Cell is called a RCCRBB Sashimi Finned Mutant Swordfish.

Again, the candidate must not be present in all Cells of Row-3, as long as it is present at least once in each of the portions of Row-3 inside Square-1 and Square-2.

The reasoning is also applicable when you replace "Column" by "Row" and "Row" by "Column".

In the example above the RCCRBB Sashimi Finned Mutant Swordfish is based on candidate 3 and it is made of Rows "B" and "J", and Column "5".
B5 is the fin Cell.
B4 is the sashimi Cell.
If candidate 3 is the solution in J6, then it is the solution either in B5, or in C5.
If candidate 3 is the solution in J9, then it is the solution either in B5, or in B6.
Whichever the solution for candidate 3 in Row "J", it can never be the solution in C4.

You can practice this strategy by installing the SudokuCoach application on your Android™ device.