: These are likely watermarks or "tags" from the third-party websites or groups that uploaded or re-encoded the file.
If you are looking for a "guide" on how to access or watch this, it is highly recommended to use official channels rather than third-party file-sharing sites, which often host low-quality rips and can contain intrusive ads or malware. HDmovie99.Com-Mami.Bhanja-MangoTV.S01E03-BDmusi...
The string you provided appears to be a specific filename for a digital video file, likely a web series episode. Based on the naming convention, : These are likely watermarks or "tags" from