diff --git a/README.md b/README.md
index 74b80e3..22b384f 100644
--- a/README.md
+++ b/README.md
@@ -232,6 +232,10 @@ of this parameter has the format `<VARIABLE_NAME>=<VALUE>`.
 
 `FAM_GEOID_SOURCE` Sets the `$globalGeoidSource` variable in `require/settings.php`. Default `egm96-15`. Optional.
 
+`FAM_ENABLE_ACARS` Sets the `$globalACARS` variable in `require/settings.php`. Default `false`. Optional.
+
+`FAM_GLOBAL_URL` Sets the `$globalURL` variable in `require/settings.php`. Default is unset. Sets the URL pathing for asset requests. Useful for running FAM behind a proxy. No trailing `/`. Optional.
+
 If you wish to use an external database:
 
 `MYSQLHOSTNAME` Sets the hostname of the mysql/mariadb server.
diff --git a/rootfs/etc/s6-overlay/scripts/03-settings b/rootfs/etc/s6-overlay/scripts/03-settings
index 10aa2cc..1ccd7c8 100755
--- a/rootfs/etc/s6-overlay/scripts/03-settings
+++ b/rootfs/etc/s6-overlay/scripts/03-settings
@@ -197,4 +197,16 @@ search="\$globalGeoidSource = '"
 replace="\$globalGeoidSource = '${FAM_GEOID_SOURCE}';"
 sed -i "/${search}/c\\${replace}" /var/www/flightairmap/htdocs/require/settings.php
 
+if chk_enabled "${FAM_ENABLE_ACARS}"; then
+  search="\$globalACARS = FALSE;"
+  replace="\$globalACARS = TRUE;"
+  sed -i "/${search}/c\\${replace}" /var/www/flightairmap/htdocs/require/settings.php
+fi
+
+if chk_enabled "${FAM_GLOBAL_URL}"; then
+  search="\$globalURL = '"
+  replace="\$globalURL = '${FAM_GLOBAL_URL}';"
+  sed -i "/${search}/c\\${replace}" /var/www/flightairmap/htdocs/require/settings.php
+fi
+
 echo ""