In custom firmware (CFW) circles, these files are often managed using homebrew tools.
Based on the version number 1.0.2 -v131072-NSP you are likely looking for a guide for the first major post-launch patch of Assassin's Creed Shadows Update 1.0.2 -v131072-NSP -
Thus, Update 1.0.2 -v131072-NSP is almost certainly a – possibly to indicate: In custom firmware (CFW) circles, these files are