--- a/code_behind.html	Mon May 13 21:24:48 2019 -0700
+++ b/code_behind.html	Wed May 15 00:00:45 2019 -0700
@@ -15,7 +15,7 @@
       file names match while only the extensions differ; e.g. <var>foo.py</var>
       will contain the code-behind logic associated with <var>foo.pspx</var>.
       Use of the <code>#python</code> and/or <code>#template</code> header
-      directives will of course change this default association.</p>
+      directives can of course change this default association.</p>
     <p>Pretty much anything can be in the code-behind files, with one
       restriction. There must be one and only one instance of a subclass of
       either <var>Page</var> (normal pages) or <var>ErrorPage</var> (error
@@ -42,6 +42,21 @@
       method; the default behavior as described in the <em>Default Template
         Variables</em> section of the template documentation is normally
       sufficient.</p>
+    <h3>Page Objects</h3>
+    <p>These contain the code-behind for normal pages. When the <var>handle</var>
+      method begins executing, they contain two instance variables: <var>request</var>
+      (a <var>bottle.Request</var> object) and <var>response</var> (a <var>bottle.Response</var>
+      object). </p>
+    <h3>ErrorPage Objects</h3>
+    <p>These contain the code-behind for error pages.&nbsp; When the <var>handle</var>
+      method begins executing, they contain two instance variables: <var>request</var>
+      (a <var>bottle.Request</var> object) and <var>error</var> (a <var>bottle.HTTPError</var>
+      object). </p>
+    <h3>The Application Context</h3>
+    <p>There is no separate standard instance variable in either <var>Page</var>
+      or <var>ErrorPage</var> that provides such, because it is available via
+      <var> request.app</var>. See the Bottle documentation for more
+      information.</p>
     <h2>Code-Behind is Optional</h2>
     <p>If you define a template with no code-behind file, TinCan will use either
       <var>Page</var> or <var>ErrorPage</var> as appropriate, which will