The code appears to be a specific filename for a video, but there is no widely recognized "official" blog post associated with this exact string in general search results. It is possible that this refers to:
(e.g., a travel vlog, a tutorial, a religious lecture, or a corporate presentation?) Who is the target audience? MANN-028.mp4
The Indian Prime Minister's radio program often uses the prefix "Mann," though its episodes are usually numbered much higher than 28 by now. The code appears to be a specific filename