Update runtime files
diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index 89a2491..5ac2f63 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -802,6 +802,8 @@
 |sub-replace-expression|.  You can use that for complex replacement or special
 characters.
 
+The substitution is limited in recursion to 4 levels. *E1290*
+
 Otherwise these characters in {string} have a special meaning:
 								*:s%*
 When {string} is equal to "%" and '/' is included with the 'cpoptions' option,