OpenCities Map defines feature classes as points, lines or polygons and associates a single set of symbology (level, color, weight, style etc.) for that class to conform with the way MicroStation displays elements.

It is common for CAD data to have many element types with many different symbologies on a single level. A roadway design might have the center line and curb lines on the same level as well as some annotation text.

When reference files are attached, they are scanned and new feature classes are created for each recognized feature type. These feature classes will have a default symbology and placement method associated with them. Because the feature recognition is based on the level name, the placement method and symbology will be based on the first element found on a particular level and, as such, may differ from other elements found on that level. For best results when integrating CAD with OpenCities Map, try to differentiate the CAD elements by level at a minimum.