The Knight move is the reference here, because after W-F you are at an N square, as the first oblique square you visit. I suppose that isnot a watertight definition, though, as you could create oblique paths that never visit an oblique square, e.g. by starting orthogonally, and then jump onto a diagonal to continue. E.g. [W-fsN], or even [W-sW-fzB] for creating a 'Fat Bishop', which cannot squeeze itself between two orthogonally adjacent pieces. Such moves have 8-fold symmetry, like all obliques, and thus a primary direction or the pairs that are each other's orthogonal mirror image, and a secondary direction to identify the member of such a pair.
The Knight move is the reference here, because after W-F you are at an N square, as the first oblique square you visit. I suppose that isnot a watertight definition, though, as you could create oblique paths that never visit an oblique square, e.g. by starting orthogonally, and then jump onto a diagonal to continue. E.g. [W-fsN], or even [W-sW-fzB] for creating a 'Fat Bishop', which cannot squeeze itself between two orthogonally adjacent pieces. Such moves have 8-fold symmetry, like all obliques, and thus a primary direction or the pairs that are each other's orthogonal mirror image, and a secondary direction to identify the member of such a pair.