From Moving Pictures
The NFO Scanner is enabled by default and looks for nfo files residing in the same folder as the movie.
If you want to change these settings you can find them in the Moving Pictures Configuration -> Advanced Settings tab. As you might have guessed it's actually a textreader that reads through all files with the extension specified in the "File Extensions" setting. It expects the contents of these files to be text-based/human readable (this includes xml based files). During reading it will stop at the first IMDB id encountered and report that back as the IMDB id for that particular movie. The IMDB id will be provided to the DataProvider/Scraper to enhance the search.
There are however certain rules that the scanner will play by:
<ext> = video extension (ex: 'avi')
<nfo> = nfo extension (default: 'nfo' and 'txt')
<movie> = the original filename of the movie without the <ext> (possible stack markers like cd1, cd2 etc.. are removed also)
1. When a folder contains just one movie (this includes multiple files stacked as one movie) -> Iterate through all files matching *.<nfo> in the current folder.
2. When a folder contains more than one movie. -> Look for files that match <movie>.<nfo> in the current folder.
Note: If you NFO file contains the wrong id (or multiple id's and the first id doesn't match the movie) the scanner can cause a false search/match. <insert magician name here> is not part of the moving-pictures dev team so there's really nothing i can do about that scenario
If you are not sure your NFO files are correct you can disable the scanner and/or disable auto-approval for IMDB id's. You should always be able to rescan the movie (even the auto-approved ones) from the importer pane with a custom search.