Super-Kamiokande 50 kton water-Cherenkov neutrino detector (Kamioka, Japan). Shared instrument behind many neutrino/proton-decay/monopole-catalysis bounds. known_biases: detector-wide energy-scale, fiducial-volume and background-modeling systematics; solar-capture and catalysis-cross-section modeling assumptions common to all catalysis-flux limits derived from it would shift every such bound together.