To Add Classifications to an AEC Polygon Style

Click Manage tab Style & Display panel Style Manager .
In the Style Manager, expand Multi-Purpose Objects AEC Polygon Styles, and select the style you want to change.
Note: Alternatively, you can select an AEC polygon in the drawing, and click AEC Polygon ribbon contextual tab General panel Edit Style drop-down AEC Polygon Styles.
Click the Classifications tab.
By default, the classification for all classification definitions is Unspecified. If no classification definitions are listed, none are applied to AEC polygon styles.

For each classification definition, select the classification you want applied to the current AEC polygon style.