-# The apt sources files we want, STRETCH_FREE, STRETCH_NONFREE,
-# BUSTER_FREE, BUSTER_NONFREE, TESTING_FREE, TESTING_NONFREE,
-# XENIAL_FREE, FLIDAS, ETIONA, STRETCH_LINODE.
+# The distro subvol name, we can add as many of these as we want:
+# VOL_TESTING, VOL_STRETCH, VOL_BUSTER, VOL_BULLSEYE, VOL_BOOKWORM
+# VOL_FLIDAS, VOL_ETIONA, VOL_NABIA
+# VOL_XENIAL, VOL_BIONIC VOL_FOCAL
+# VOL_BUSTER_BOOTSTRAP.
+# Using VOL_BUSTER_BOOTSTRAP sets up the install to act like a pxe rom if
+# grub sets a specific var.
+#
+# The apt sources files we want,
+# STRETCH_FREE, STRETCH_NONFREE,
+# BUSTER_FREE, BUSTER_NONFREE,
+# BULLSEYE_FREE, BULLSEYE_NONFREE
+# BOOKWORM_FREE, BOOKWORM_NONFREE
+# TESTING_FREE, TESTING_NONFREE,
+# XENIAL_FREE, BIONIC, FOCAL, FLIDAS, ETIONA, NABIA, STRETCH_LINODE.