+
+`systemd-mountfsd`:
+
+* `$SYSTEMD_MOUNTFSD_TRUSTED_DIRECTORIES` – takes a boolean argument. If true
+ disk images from the usual disk image directories (`/var/lib/machines/`,
+ `/var/lib/confexts/`, …) will be considered "trusted", i.e. are validated
+ with a more relaxed image policy (typically not requiring Verity signature
+ checking) than those from other directories (where Verity signature checks
+ are mandatory). If false all images are treated the same, regardless if
+ placed in the usual disk image directories or elsewhere. If not set defaults
+ to a compile time setting.
+
+* `$SYSTEMD_MOUNTFSD_IMAGE_POLICY_TRUSTED`,
+ `$SYSTEMD_MOUNTFSD_IMAGE_POLICY_UNTRUSTED` – the default image policy to
+ apply to trusted and untrusted disk images. An image is considered trusted if
+ placed in a trusted disk image directory (see above), or if suitable polkit
+ authentication was acquired. See `systemd.image-policy(7)` for the valid
+ syntax for image policy strings.
+
+`systemd-run`, `run0`, `systemd-nspawn`, `systemd-vmspawn`:
+
+* `$SYSTEMD_TINT_BACKGROUND` – Takes a boolean. When false the automatic
+ tinting of the background for containers, VMs, and interactive `systemd-run`
+ and `run0` invocations is turned off. Note that this environment variable has
+ no effect if the background color is explicitly selected via the relevant
+ `--background=` switch of the tool.