: Use a tool like MediaInfo or right-click the file and select "Properties" (Windows) or "Get Info" (Mac) to see the "Date Created" or "Encoded Date," which can give you a clue about its source.
: Most likely a sequential ID number, a date (September 26th), or a specific location/camera code. DVDES-926-ES.mp4
If you have come across this file on a local drive or received it via email: : Use a tool like MediaInfo or right-click
: Files named with rigid alphanumeric strings are common in discovery phases of legal proceedings or forensic reports. Recommendations for Handling a date (September 26th)