Once the device reaches a high number (like S9999 ), it typically starts over at S0001 , deleting the oldest files to make room for new ones.
This indicates it is the 86th video recorded in that specific session or folder. S0086 mp4
If you can tell me what device recorded this (e.g., a Garmin dashcam, a Samsung phone, a drone) or where you saw the name, I can give you a much more specific technical feature list for that exact model. Which device or app produced this file? Once the device reaches a high number (like