General information regarding production codes and studio history is often used by archivists to catalog media from this sector of the entertainment industry.
The filename appears to refer to a specific video production from the Japanese adult media industry. Context and Identification IPX-377-MR.mp4
The video was originally released around September 2019. The "MR" suffix in the filename often indicates a "Media Render" or a specific encoded version of the original file. Studio and Performer Profile IPX-377-MR.mp4