--- a/bin/fpkg	Fri Sep 06 22:07:38 2019 +0200
+++ b/bin/fpkg	Fri Sep 06 22:08:19 2019 +0200
@@ -42,6 +42,26 @@
   upgrade-check
 
     `pkg upgrade -n` on the local host and all running visible jails
+
+ENVIRONMENT:
+
+  AUDIT_FLAGS
+                 Additional flags given to `pkg audit`
+                 (Default: -Fr)
+
+  UPDATE_FLAGS
+                 Additional flags given to `pkg update`
+                 (Default: empty)
+
+  UPGRADE_FLAGS
+                 Additional flags given to `pkg upgrade` and `pkg upgrade -n`
+                 (Default: empty)
+
+  SIGN
+                 Marker for the begin of an output group (local host or jail)
+                 (Default: "===> ")
+
+  All other environment variables that affect `pkg` are effective also.
 '
 
 : ${AUDIT_FLAGS:=-Fr}