- rearranging rows withing the same 3-row block (idem with columns)
- rearranging the order of the 3-row blocks (idem with 3-column blocks)
- permutating 123456789 into a different order
- transposing the grid (making rows into columns and vice versa)
PS the title of this article refers to "the myth of the fingerprints" by Paul Simon. "I've seen them all and man, they're all the same..."