// Software Production Line
Some version of Microsoft Windows OS have rather dangerous subsystem known as MP4 property sheet handler (“MF MPEG-4 Property Handler” to be exact). Programmatically, you would use API like SHGetPropertyStoreFromParsingName and use IPropertyStore from there to read (reading is OK) and update/write certain MP4 file properties like, for example, a comment or som other metadata.
The same API is used from property sheet UI if you decide to update metadata: