Shows the top level of a single part, cast unit, assembly, part of a connection or a pour object.

Top level takes the unit and accuracy from MarkDimensionFormat.dim. You can modify the settings in MarkDimensionFormat.dim in the Dimension Properties dialog box in a drawing.

The datum level only affects the TOP_LEVEL attribute when Location by is set to Model origin or to the project base point that is in the model origin.

You can use this attribute as a user-defined attribute also in part marks and associative notes.