From Rare Gaming Dump

Nintendo Release Server, mainly known as NRS, was a file server used by BroadOn, NCL, and IRD to share and distribute files between each other during the development of the Wii and other related development projects at the time.

Before any dumps of NRS or any of the contents of NRS were leaked, there were multiple mentions of NRS in the files from unsorted.7z, which were not noticed by a majority of people prior to the wiidump.7z and ios-releases.tar.7z leak.