Decide what each video represents
An alternative encode of a film and a making-of interview belong to different parts of a movie item. Start by identifying the intended role of each file. A second main-library entry might be an incorrectly grouped encode; an interview treated as a main feature might instead need an extras pattern. Sorting both problems with the same naming rule makes the result harder to understand.
Match the full prefix for movie versions
Jellyfin’s movie guide requires each version filename to begin with the complete parent folder base name, including a year or provider identifier when present. The match is character for character, before a supported separator and version label. A shortened title with the year removed therefore fails that documented condition even when its resolution label looks sensible. The guide also describes version ordering and the default choice, so inspect the version menu after correcting a small sample.
Identify bonus material as extras
For extras, Jellyfin documents recognised subfolder names and particular filename suffixes. These are separate patterns: do not copy a folder name containing spaces into a suffix whose documented form has no spaces. Choose a supported extra type that describes the material, such as an interview or trailer, rather than calling a short film a second quality version of the feature.
Check one production before renaming the archive
Imagine an independently produced film stored in a folder whose name contains its release year. Compare both full-length encodes with that exact folder name, then put the director interview into a recognised extras structure. Preserve the original names in a simple change note before editing. After the supported scan, confirm that the feature has the intended version choices, the interview is associated with the correct film, and neither appears as an unexplained standalone duplicate. This small check gives you a repeatable pattern for the rest of that archive without assuming that a quality label can describe every creative edition.
Questions, answered
Should a bonus interview use the same naming rule as a second encode?
No. Alternative movie versions use the exact folder-prefix rule; extras use their documented folder or suffix patterns.