I wasn't sure about whether this should be an issue or not. The points I mentioned could be figured out by intuition, but I felt like they weren't clear from reading the discription.
Thank you for updating the description; I marked the Kata as Ready.

While the goal of this Kata is not too hard to figure out, in my opinion the Kata's description is not complete. At the very least, the description should mention that the i-th letter in the latin alphabet maps to the i-th (assuming 1-based indexing) element in the array. It should also mention the way upper-case letters are to be transformed.