Each REF argument is a full or partial identifier in the flatpak ref format, which looks like "(app|runtime)/ID/ARCH/BRANCH". All elements except ID are optional and can be left out, including the slashes, so most of the time you need only specify ID. Any part left out will be matched against what is installed, and if there are multiple matches you will be prompted to choose between them. You will also be prompted if REF doesn't match any installed ref exactly but is similar (e.g. "gedit" is similar to "org.gnome.gedit").
By default this looks for both installed apps and runtimes with the given REF, but you can limit this by using the --app or --runtime option, or by supplying the initial element in the REF.
Normally, this command removes the ref for this application/runtime from the local OSTree repository and purges any objects that are no longer needed to free up disk space. If the same application is later reinstalled, the objects will be pulled from the remote repository again. The --keep-ref option can be used to prevent this.
When --delete-data is specified while removing an app, its data directory in ~/.var/app and any permissions it might have are removed. When --delete-data is used without a REF, all 'unowned' app data is removed.
Unless overridden with the --system, --user, or --installation options, this command searches both the system-wide installation and the per-user one for REF and errors out if it exists in more than one.
The following options are understood:
$ flatpak --user uninstall org.gnome.gedit