diff --git a/adapter-cqld4/src/main/resources/cqld4.md b/adapter-cqld4/src/main/resources/cqld4.md
index d1241eb4a..256ee7fca 100644
--- a/adapter-cqld4/src/main/resources/cqld4.md
+++ b/adapter-cqld4/src/main/resources/cqld4.md
@@ -69,6 +69,8 @@ nb5 ... driverconfig='http://gist.github.com...'
 * **showstmt** - enable per-statement diagnostics which show as much of the statement as possible
   for the given statement type. *WARNING* - Do not use this for performance testing, only for
   diagnostics.
+* **diag** - a set of options for advanced diagnostics for CQL. Defaults to `diag=none`.
+  Valid values are  none, addr, mid, all. Presently, only none and all are supported.
 * **maxpages** - configure the maximum number of pages allowed in a CQL result set. This is
   configured to `maxpages=1` by default, so that users will be aware of any paging that occurs
   by default. If you expect and want to allow paging in your operation, then set this number