Coble surfaces in characteristic two

K3 surfaces of Kummer type in characteristic two

“…Note that a configuration of type $$(4_3)$$ is realized by two sets of lines among 20 lines on an octic model of the Kummer surface in characteristic two [20, Figure 2].…”

“…The relationship with the quadratic line complexes is studied in a recent paper of T. Katsura and S. Kondō [20]. In characteristic 2, a pencil of quadrics in $$\mathbb {P}^5$$ with smooth base locus $$Y$$ has three (instead of six) singular quadrics.…”

“…The paper should be considered as a lengthy footnote to [20]. I am thankful to the authors for a helpful discussion.…”