diff --git a/src/ca/CAref.html b/src/ca/CAref.html
index ab3a775dc..acd1c67ff 100644
--- a/src/ca/CAref.html
+++ b/src/ca/CAref.html
@@ -2439,7 +2439,7 @@ channel names in the test are numbered as follows.</p>
 <p>&lt;PV name&gt;000000, &lt;PV name&gt;000001, ... &lt;PV name&gt;nnnnnn</p>
 
 <h3><a name="casw">casw</a></h3>
-<pre>casw</pre>
+<pre>casw [-i &lt;interest level&gt;]</pre>
 
 <h4>Description</h4>