diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
index fd4237c64fb2..e2056c8b902c 100644
--- a/samples/landlock/sandboxer.c
+++ b/samples/landlock/sandboxer.c
@@ -234,7 +234,22 @@ int main(const int argc, char *const argv[], char *const *const envp)
 	/* Best-effort security. */
 	switch (abi) {
 	case 1:
-		/* Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2 */
+		/*
+		 * Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2
+		 *
+		 * Note: The "refer" operations (file renaming and linking
+		 * across different directories) are always forbidden when using
+		 * Landlock with ABI 1.
+		 *
+		 * If only ABI 1 is available, this sandboxer knowingly forbids
+		 * refer operations.
+		 *
+		 * If a program *needs* to do refer operations after enabling
+		 * Landlock, it can not use Landlock at ABI level 1.  To be
+		 * compatible with different kernel versions, such programs
+		 * should then fall back to not restrict themselves at all if
+		 * the running kernel only supports ABI 1.
+		 */
 		ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER;
 		__attribute__((fallthrough));
 	case 2: