Drawing standards (DWS) files are used by the CAD Standards and Batch Standards Checkers in addition to storing layer mappings used by the Layer Translator.
If you create a new drawing standards (DWS) file, it is saved in the native drawing file format for the release in which it is created. If you make changes to a DWS file that might need to be used with an earlier release, you will need to save the DWS file as a DWG file in the earlier drawing file format and then change the extension of the DWG file in File Explorer from .dwg to .dws.
For changes to the drawing file format that might affect the DWS files you create or use, see About Drawing (DWG) File Changes.