There is only one file type that uses the .NRF extension:
Neat Document Folder File
Document folder file created by NeatWorks, a digital document organizing application; contains an exported copy of a Neat document folder that can be shared between Neat users; replaced by the .NDX extension when Neat 5 was released.
To create a NRF file using NeatWorks (older version of Neat 5) select, choose the save location, name the file, and click .
To import a NRF file into Neat 5, select, click "Browse," navigate to your NRX file, and click .
NOTE: The NRF file is similar to .NRT and .NRX files, which are used by older versions of Neat.
Updated: June 12, 2016