These are likely "Scene Tags" or group identifiers, indicating which release group processed the file or which tracker it originated from. Why "Remux" Matters
Constant bit-rate AVC, preserving the original film grain. cm untamedheart1993720pblurayremuxavcf top
This is the most important tag. A "Remux" means the video and audio tracks have been stripped from the disc and put into a container (like .mkv) without any additional compression. You are getting the exact quality found on the physical disc. These are likely "Scene Tags" or group identifiers,