"MCSR" typically refers to the volume and page number of a case (e.g., 36 MCSR 1 refers to Volume 36, Page 1). "502" may refer to Page 502 of a specific volume.
This appears to be a reference to a specific document or file within the (MCSR), likely found in a legal database or public records archive. MCSR-502.mp4
It may be a standardized file name for a long-form video evidence submission in a civil service appeal. "MCSR" typically refers to the volume and page
Where did you see this (e.g., a specific website or a legal document)? Keady, Michael v. Boston Fire Department 4/16/26 - Mass.gov MCSR-502.mp4
If you can provide more context, I can help narrow this down: Do you have a or a year ?