man 5 flatpak-installation

FLATPAK INSTALLATION(5)      flatpak installation      FLATPAK INSTALLATION(5)

NAME
       flatpak-installation - Configuration for an installation location

DESCRIPTION
       flatpak can operate in system-wide or per-user mode. The system-wide
       data is located in $prefix/var/lib/flatpak/, and the per-user data is
       in $HOME/.local/share/flatpak/.

       In addition to the default installation locations, more system-wide
       installations can be defined via configuration files
       /etc/flatpak/installations.d/, which must have the .conf extension and
       follow the format described below.

FILE FORMAT
       The installation config file format is using the same .ini file format
       that is used for systemd unit files or application .desktop files.

   [Installation ...]
       All the configuration for the the installation location with name NAME
       is contained in the [Installation "NAME"] group.

       The following keys are recognized:

       Path (string)
           The path for this installation. This key is mandatory.

       DisplayName (string)
           The name to use when showing this installation in the UI.

       Priority (integer)
           A priority for this installation.

       StorageType (string)
           The type of storage used for this installation. Possible values
           include: network, mmc, sdcard, harddisk.

EXAMPLES
           [Installation "extra"]
           Path=/location/of/sdcard
           DisplayName=Extra Installation
           StorageType=sdcard

flatpak                                                FLATPAK INSTALLATION(5)