Help wanted with phrasing of rules (and their German translation.)

[Abdul the Killer]

Thanks again, Dandelo and euclid. Both of your suggestions contain a kernel of good ideas. As it is I've recently changed "diagonally or orthogonally" to "diagonal or orthogonal" which somewhat improves the grammar.

If anyone finds the formulations proposed by Dandelo or euclid more appropriate, or have other ideas please comment.