Peter Beelen and guest Ph.D. Maria Montanucci have solved a conjecture on the structure of Weierstrass semigroups for certain points on the Giulietti-Korchmaros maximal curve. This conjecture was posed in 2011 in the article Two-Point Coordinate Rings for GK-Curves, IEEE Trans. Inf. Theory 57(2), 593-600 by I. Duursma. Apart from proving the conjecture, Peter and Maria in fact determined the structure of the Weierstrass semigroup of any point on the GK curve. A preprint of these results is available here.