how to add a custom item to "more infos"

> - can I just add a new subfolder to
> C:\ProgramData\Squeezebox\Cache\InstalledPlugins\P lugins ? (and maybe
> restart LMS)

No. Don't touch the InstalledPlugins folder. Never. Check
Settings/Information for the real Plugins folder you're looking for.

> - I see all of the plugin subfolders (in path above) have a "HTML"
> subfolder. Is this mandatory, or can I just -not- include one ? (not
> sure what it's used for)

HTML is only required if you want to provide a web UI for some aspect of
your plugin. The web template would go in there, icons, images etc.

--

Michael