The addition of the .mp4 extension indicates that the media has been digitized into the format. This is the industry standard for a reason:
Offers a high degree of compression without significant loss of visual quality. SHKD-820.mp4
Helping viewers find other works by the same director or lead performers. The addition of the
For fans of specialized cinema, these codes are more than just labels. They allow for: SHKD-820.mp4
Allows for the embedding of subtitles, chapter markers, and cover art. Why Production Codes Matter