diff --git a/share/colldef/README b/share/colldef/README
new file mode 100644
index 000000000000..015f0003c907
--- /dev/null
+++ b/share/colldef/README
@@ -0,0 +1,6 @@
+$FreeBSD$
+
+WARNING: Collating table can't be in the free form, but backward
+compatible with ASCII only, i.e. other symbols can be added to
+the existen ASCII order.
+