There is only one file type that uses the .RLF extension:
ArcGIS Report Layout File
Report template created by ArcGIS Desktop geospatial visualization and analysis software; stores the layout for a report and includes template fields and source data information; used for generating geospatial reports (.RDF files).
RLF files are created with the Report Designer included with ArcGIS Desktop.
|ESRI ArcGIS for Desktop||Commercial|
Updated: May 23, 2012