There is only one file type that uses the .NRL extension:
Autonomy Interwoven Link File
4.5 (4 votes)
File used by Interwoven content management system (CMS) solutions, which organize company-wide digital resources and help to manage work flow; contains a link reference to a resource within the CMS; saved in text format with a library name, document, and version number.
Autonomy Interwoven was formerly known as iManage.
Updated: November 26, 2009