Penetration Holes: SDNF does not allow the description of holes within Linear Members.
Additional data: SDNF is a poor transfer format as you have few means by which extra information can be transferred between systems.
Nodal Model: Connectivity is difficult to reconstruct once lost. SDNF does not transfer the information.
Templates: Catalogues are not covered by SDNF. Linear or Arc members and Plates contained in Templates or Groups are transferred on export. There is no facility for constructing a new Template or Group on import. Elements that are in pre-existing Templates or Groups are compared and merged, but new elements are not placed in the same container.
Non-prismatic end details: SDNF
Packet 10 cannot describe any details at member/cleat ends apart from full orthogonal cuts. For example, all sloped cuts and notches are approximated from minimum to maximum local longitudinal co-ordinate, which should be conservative regarding clash detection. SDNF
Packet 20 can describe only fully prismatic Plates. Hence, the Plate cuts/intersections which are not fully orthogonal to the Plate's local plane cannot be mapped to SDNF. Such Plates are exported 'uncut', which again should be conservative for clash detection.