creo4 config.pro option documentation for: INTF2D_OUT_IGES_LAYERS_WITH_ID 
intf2d_out_iges_layers_with_id
yes
, no
*
Determines the export of layer IDs of drawings to the IGES format.
yes
- Exports the layer IDs of drawings, instead of layer names, to the IGES format. The layer IDs are mapped to IGES levels.
no
- Layers are mapped to IGES levels by their names and internal IDs, regardless of their user IDs. This is the default value.