By default, AutoCAD Map 3D considers MapInfo MIF/MID a multi-select, file-based format, that is, you select one or more individual .mif files during a single import process. To change the default so that AutoCAD Map 3D considers MIF/MID a folder-based format (all files in the folder are included in the import) or a single-select format (only one file can be selected for import), modify the settings in the mapimport.ini file.
Symbol types are similar to AutoCAD Map 3D point objects. You cannot import MIF/MID symbol types directly. However, if you store the symbol type information in a column in a MID file, you can map each symbol type to a block in the current AutoCAD Map 3D drawing. To do this, prepare the MIF file by putting the name of the symbol type into a field in the database. Prepare the AutoCAD Map 3D drawing by creating similar symbols as blocks in the AutoCAD Map 3D drawing. Then, during import, perform a point-block mapping and select the check box to get the block name from data and select the symbol type field you created.
In MapInfo, polygons are represented as closed areas. When you import polygons into AutoCAD Map 3D, they appear as polygons unless you select Import Polygons As Closed Polylines in the Import dialog box.