On the Text & Fonts tab of the Modify DWG/DXF Export Setup dialog (see Exporting to DWG or DXF), you can specify the degree of visual fidelity that will be maintained upon export. You can also map Revit text fonts to specific DWG/DXF text fonts as needed.
From the Text treatment during export drop-down list, select one of the following options:
By default, all the Revit fonts listed in the mapping table have a value of {Automatically map font} in the Text Fonts in DWG column, which means the Revit font will be maintained in the exported file. If you want to map a Revit font to a specific DWG text font, click the value for that font in the Text Fonts in DWG column, and then select the desired font from the drop-down list.
You can click Reset All to change all the DWG font values in the table back to {Automatically map font}. Alternatively, you can multi-select rows and click {Automatically map font}.