diff --git a/man/systemd-notify.xml b/man/systemd-notify.xml
index 9bb35a3a0c..8c56a6b8ed 100644
--- a/man/systemd-notify.xml
+++ b/man/systemd-notify.xml
@@ -83,6 +83,13 @@
sd_notify() message and immediately exits, the service manager might not be able to properly
attribute the message to the unit, and thus will ignore it, even if
NotifyAccess= is set for it.
+
+ systemd-notify will first attempt to invoke sd_notify() pretending to
+ have the PID of the invoking process. This will only succeed when invoked with sufficient privileges. On failure,
+ it will then fall back to invoking it under its own PID. This behaviour is useful in order that when the tool is
+ invoked from a shell script the shell process — and not the systemd-notify process — appears as
+ sender of the message, which in turn is helpful if the shell process is the main process of a service, due to the
+ limitations of NotifyAccess= described above.