Penetration Holes: SDNF does not allow the description of holes within Linear Members.

Additional data: SDNF is a poor transfer format as the user has 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 will be 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 will be compared and merged, but new elements will not be 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. Hence, all sloped cuts, notches, etc. will be 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 will be exported 'uncut', which again should be conservative for clash detection.