So this may be a little arcane...
I've been trying to figure out why some of the 'extras' contained within extras folders of my movie folders are having nfo/jpg files created for them and showing up in the movie index, no matter what i do to rename them or delete the nfo file.
I think i’ve figured out what the issue is.
It seems that if there are multiple ‘main’ movies in the root of the movie folder, some of the files in the extras folder will be identified as their own movie rather than an extra for one of the existing movies.
For example, i have
\Movies\Robin Hood (1973)