diff --git a/man/os-release.xml b/man/os-release.xml
index 4acd1a9a575..7e3e9a73a8c 100644
--- a/man/os-release.xml
+++ b/man/os-release.xml
@@ -75,6 +75,10 @@
from earliest boot on, and hence must be located on the root file
system.
+ os-release must not contain repeating keys. Nevertheless, readers should pick
+ the entries later in the file in case of repeats, similarly to how a shell sourcing the file would. A
+ reader may warn about repeating entries.
+
For a longer rationale for os-release
please refer to the Announcement of /etc/os-release.