How do we use the ProgID column in the File Associations settings?
It's a name that uniquely identifies the file type. So a description might be "Document created with Microsoft Word" and the ProgID might be "Word". If your app name is short, you can just put that in there. If your app name isn't short, put in some abbreviation of it.
Some examples from the registry subkeysHKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\ ~ \OpenWithProgids:
- .bmp -
Paint.Picture - .csproj -
VisualStudio.Launcher.csproj.15.0 - .csv -
Excel.CSV - .docx -
Word.Document.12 - .mp4 -
WMP11.AssocFile.MP4