Creating CAD-defined feature classes
There are three ways to create CAD-defined feature classes:
Exporting data to AutoCAD drawings
By default, exporting data to AutoCAD drawings generates CAD-defined feature classes.
For each input feature class, the Export To CAD tool embeds a feature class definition in the AutoCAD drawing file, comprising the default AutoCAD entities that are generated for the feature. All feature attributes are exported as AutoCAD xrecords and linked to the appropriate entities. Similarly, the coordinate system is also exported and embedded in the DWG file.
ArcGIS for AutoCAD
ArcGIS for AutoCAD is an ESRI extension for AutoCAD that enables AutoCAD to share information and data with ArcGIS Desktop and ArcGIS Server. Using ArcGIS for AutoCAD, you can create CAD-defined feature classes, import schemas from other DWG files, or edit CAD-defined feature classes created by the Export To CAD tool.
CAD-defined feature classes are defined with schemas that conform to ESRI's Mapping Specification for CAD. Feature class schemas and entity-linked attributes created with third-party applications that conform to this open-source specification are recognized by ArcGIS as read-only CAD feature classes.
For detailed information about how this data is structured, reference the ESRI document Mapping Specification for CAD available on the ArcGIS for AutoCAD Resource Center.