Comment # 7 on bug 984332 from Dominique Leuenberger

(In reply to Michael Andres from comment #6)
> Different items need different names, 
> 
> - so either we need to avoid duplicate application names 
>   [appdata creation]

AppStream builder already denies duplicate names on desktop items... not on
extensions though (as a 'spell check' plugin can exist for multiple
applications.. .and calling them 'FOO spell check', while obviously meant for
foo based on the <extends> property, makes not much sense)

> - or we need some additional scope like:
>     application:GPaste-shell-extension
>     application:GPaste-desktop
>   (provided the scope can be deduced for installed applications)
>   [libsolv parser]

application:GPaste (based on desktop) is added to the appstream metadata based
on /usr/share/appdata/org.gnome.GPaste.Ui.appdata.xml

The gnome-shell extension is added to the appstream metadata based on
/usr/share/gnome-shell/extensions/GPaste@gnome-shell-extensions.gnome.org/metadata.json
(every installed gnome-shelle extension has a file
/usr/share/gnome-shell/extensions/*/metadata.json)