  We report the identification of symmetry-enforced nodal planes (NPs) in CoSi
providing the missing topological charges in an entire network of
band-crossings comprising in addition multifold degeneracies and Weyl points,
such that the fermion doubling theorem is satisfied. In our study we have
combined measurements of Shubnikov-de Haas (SdH) oscillations in CoSi with
material-specific calculations of the electronic structure and Berry curvature,
as well as a general analysis of the band topology of space group (SG) 198. The
observation of two nearly dispersionless SdH frequency branches provides
unambiguous evidence of four Fermi surface sheets at the R point that reflect
the symmetry-enforced orthogonality of the underlying wave functions at the
intersections with the NPs. Hence, irrespective of the spin-orbit coupling
strength, SG198 features always six- and fourfold degenerate crossings at R and
$\Gamma$ that are intimately connected to the topological charges distributed
across the network.
