Logic Masters Deutschland e.V.

Normal sudoku rules apply (digits 1-6 without repeats in every row, column, region)

Taxicab: For any digit N, no two instances of the digit may have a Manhattan distance of exactly N.

Index Lines: If Xth digit on an index line is Y, the Yth digit on that line is X. The first is denoted with a square rotated 45°

Potentially Helpful Hints:
Manhattan distance is the number of one-cell orthogonal movements to get from one cell to another. Counting steps can make it easier to check which cells to eliminate digits from, using the Taxicab constraint.
Due to the way index lines work, there can be no repeating digits along an index line and the digits along an L-cell index line are the numbers from 1-L