When importing an FBX file, most of the settings are self-explainable, however, there are some settings that I'm curious to know the meaning/use of. These are: (1) Import User Properties (what are user properties in a FBX file, doesn't FBX only store meshes, textures and animations?). (2) Import Enums As Strings (what are enums and strings?). (3) Use Pre/Post Rotation (what are pre/post rotation?). Hovering the mouse over these in Blender doesn't explain them very well, and the Blender manual just says "TODO." on these (https://docs.blender.org/manual/en/2.80/addons/io_scene_fbx.html).