man: document that systemctl cat shows file content (#4488)

... and that that content might be outdated.

diff --git a/man/systemctl.xml b/man/systemctl.xml
index a4d4c5372546955c8cd73005214601d9b02ba83a..225eb06d8b4e9bf29b2ab27c11f476f25bf0dcf4 100644 (file)
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -894,7 +894,11 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
             <para>Show backing files of one or more units. Prints the
             "fragment" and "drop-ins" (source files) of units. Each
             file is preceded by a comment which includes the file
-            name.</para>
+            name. Note that this shows the contents of the backing files
+            on disk, which may not match the system manager's
+            understanding of these units if any unit files were
+            updated on disk and the <command>daemon-reload</command>
+            command wasn't issued since.</para>
           </listitem>
         </varlistentry>
         <varlistentry>