Add information on parameter kinds
diff --git a/examples/bank/index.html b/examples/bank/index.html
index 048cbed..e1afc50 100644
--- a/examples/bank/index.html
+++ b/examples/bank/index.html
@@ -85,10 +85,25 @@
To create a new transformation rule, use the <i>Rule</i> tool
in the palette. In the top of every rule, its name and parameters
are specified (and some optional information which we do not consider
-here). In the below example, we write <i>createAccount(client, accountId)</i>,
+here).
+
+<p>
+<b>Parameters:</b>
+In the below example, we write <i>createAccount(in client:EString, in accountId:EInt)</i>,
where the <i>client</i> parameter is the name of the client for whom
an account should be created, and <i>accountId</i> is the ID to be used
for the new account.
+A parameter has a kind, which can be either
+<i>in</i>, <i>out</i>, <i>inout</i>, or <i>var</i>.
+An <i>in</i> parameter is passed into the rule from the
+rule's context.
+An <i>out</i> parameter is passed out of the rule into the
+rule's context.
+An <i>inout</i> parameter is both passed both into and out of the rule, to and from its context.
+A <i>var</i> parameter or <i>variable</i> is used internally inside a rule only.
+Optionally, a parameter also has a type, like <i>EString</i> and <i>EInt</i> in the example.
+You can change the kind, type and name of a parameter simply by typing this information into bar at the top of the rule.
+
</p>
<p>
