  We extend our previous classification of stacky curves in positive
characteristic using higher ramification data and Artin-Schreier-Witt theory.
The main new technical tool introduced is the Artin-Schreier-Witt root stack, a
generalization of root stacks to the wildly ramified setting. We then apply our
wild Riemann-Hurwitz theorem for stacks to compute the canonical rings of some
wild stacky curves.
