> For the complete documentation index, see [llms.txt](https://autodesk.ifc-manual.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://autodesk.ifc-manual.com/revit/ifc-export-category-mapping/export-for-layer-based-software.md).

# Export for Layer-based Software

Some software products may require a layer structure to be added to the IFC classification. Revit automatically assigns the layer value according to the default CAD (.dwg/.dgn) mapping file. The default configuration file is: C:\ProgramData\Autodesk\ RVT 20xx\exportlayers-dwg-AIA.txt

The configuration found in this file can be adapted from the Revit UI when selecting Export > Options > Export settings DWG/DXF or manually using the syntax:

\<Revit Category Name>\<tab>\<tab>\<Layer Name>

<figure><img src="/files/gQpurGZm5PVPAvKp5ns7" alt=""><figcaption></figcaption></figure>

The reference to a custom layer reference file needs to be added to the Revit.ini file which can be found in the following location: C:\Users\\\<USER>\AppData\Roaming\ Autodesk\Revit\Autodesk Revit 20xx

The full path to the layer reference file is added in the line starting with ExportLayersNameDGN=

For Example: ExportLayersNameDGN=C:\Users\\\<USER>\Documents\RevitLayers.txt Just like with the class mapping, sometimes it is needed to assign the layer value on the element level. For this, you can use the shared parameter *IfcPresentationLayer,* which is of course included in the official shared parameter files.