Consolidated knowledge of CLT properties under in-plane shear is crucial for typical structural applications such as wall and floor diaphragms, cantilevered CLT walls and CLT used as (deep) beams, in all cases potentially featuring holes or notches. The current technical approvals for CLT products contain differing regulations to determine their load-carrying capacities in-plane. Generally they imply a verification of the torsional stresses in the cross-section of the cross-wise glued elements as well as a verification of the shear stresses proportionally assigned to the boards of the top and cross layers. The basis of theoretical and practical considerations are the following three basic failure scenarios for a CLT-element under in-plane shear: (i) gross-shear (longitudinal shearing in all layers), (ii) net-shear (transverse shearing in all layers in weak direction), and (iii) torsion failure in the gluing interfaces between the layers.