diff --git a/scripts/redeploy-fleetd.sh b/scripts/redeploy-fleetd.sh
index 5d46f28..0095b31 100755
--- a/scripts/redeploy-fleetd.sh
+++ b/scripts/redeploy-fleetd.sh
@@ -306,10 +306,12 @@ systemd_loaded() {
 #      never assigned to a global: a global set inside a `$( )` subshell dies with that subshell.
 #      This function packs BOTH values (kind and detail) onto that one stdout line, joined by
 #      $SUPERVISOR_DETAIL_SEP, and the caller unpacks them on its own side of the subshell boundary.
-#   2. This script runs under `set -euo pipefail` (line 50), so an unset variable is a loud
-#      failure. Do not add a `${VAR:-default}` anywhere downstream to paper over a value that
-#      should always be there — that hides a lost value instead of surfacing it (fleetd #497's
-#      defect class).
+#   2. This script runs under `set -u` (part of the `set -euo pipefail` at the top of the file), so
+#      an unset variable is a loud failure. Do not add a `${VAR:-default}` anywhere downstream to
+#      paper over a value that should always be there — that hides a lost value instead of
+#      surfacing it (fleetd #497's defect class). The mechanism is named rather than cited by line
+#      number on purpose: a line number in a comment goes stale on the next insert above it, and
+#      this one already had — it said line 50 while the `set` line was at 54.
 #   3. Every `case` on this function's return value needs an explicit final `*)` arm, chosen by
 #      whether that caller ACTS on the value (`die` — an unrecognised value must never be silently
 #      driven) or only DISPLAYS it (`echo`/`warn` and continue — a diagnostic must not go silent on