Atid-476-mr-es.mp4 -

A user-submitted file or document from a private training or learning system. A media file from a specific, secure digital archive.

A file name generated by a specific company's internal naming convention. ATID-476-MR-ES.mp4

If this is a file you have access to, I recommend checking the system or platform where you first encountered it. A user-submitted file or document from a private