There are several collections out there, Looney Tunes Golden Collection, and Lord of the Rings Trilogy, being a couple, which would benefit from having support from Plex Server for a naming convention for the grouping of movies, showing which volume or disk they belong to in that Collection.
They are not really “Episodes”, since they are not a TV Show Series, but would benefit from being organized together.
Looney Tunes are actually episodes of a tv-show. The “Golden Collection” is just a subset of episodes packaged on discs (you’ll find that kind of stuff for other shows as well)
As for naming… how and why should it matter to Plex on which disc a video from the Lord of the Rings trilogy had originally been stored? If you get 2 video files because they authored the movie in 2 halves… you can either merge the resulting files (e.g. using MKVToolnix) or use the existing naming schema to identify them to Plex as “stacked files” (multi-file movies or episodes).
Example:
Movies <- the folder linked to your Plex movie library
The Lord of the Rings - The Fellowship of the Ring (2001)
The Lord of the Rings - The Fellowship of the Ring (2001) - part1.ext
The Lord of the Rings - The Fellowship of the Ring (2001) - part2.ext
The Lord of the Rings - The Two Towers (2002)
The Lord of the Rings - The Two Towers (2002).ext
If you desperately need some technical or physical details about the file, you can use disc1 and disc2 instead of part1 and part2.
When you’re dealing with files you don’t need to “stack” you can also include technical/physical details about the files and their origin in square brackets after the regular file name Example:
TV Shows <- the folder linked to your Plex tv-show library
Looney Tunes
Season 1930
Looney Tunes - s1930e01 - Sinkin' in the Bathtub [Box 1, Disc 3, Track 4].ext
Edit / additional note:
As for Looney Tunes and as mentioned above… they are tv show episodes.
As for The Lord of the Rings (or other franchises / movie series)… that’s what collections are for. If you’re using the new (non-legacy) “Plex Movie” agent for your movie library, you can configure Plex to automatically create a collection if it finds movies that belong together (most users only enable this for a minimum of 2 movies to avoid ending up with 1-movie collections)