If the key "catalogparts" is set on 1, an exported part cannot be changed in CAD. Exceptions for raw materials such as semi-finished products can be defined. In this case, set the key "catalogparts(rawmaterials)" on 0.
In PDM/ERP environments different workflows can be desired: For example, if a semi-finished product shall not get an SAP/ERP number, because it will be changed subsequently (length/chamfer/hole).