Create or modify layer mapping to ensure that all the model information stored in Revit categories and subcategories are exported to the proper CAD layers (or levels, if exporting to DGN).
Revit automatically maps categories and subcategories to preconfigured layer names. For example, a Revit door object automatically maps to A-DOOR layer in AutoCAD.
You can change the preconfigured layer/level names and modify other export settings. For DGN, the information is saved in text files (see Export to DGN). For DWG and DXF, it is saved in export setups.
For any of these formats, you can load an existing layer mapping file (current or legacy) and manually change values for it, or you can load layer settings from any of the following mapping standards: