--- /dev/null
+#data
+<isindex>
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| <form>
+| <hr>
+| <label>
+| "This is a searchable index. Enter search keywords: "
+| <input>
+| name="isindex"
+| <hr>
+
+#data
+<isindex name="A" action="B" prompt="C" foo="D">
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| <form>
+| action="B"
+| <hr>
+| <label>
+| "C"
+| <input>
+| foo="D"
+| name="isindex"
+| <hr>
+
+#data
+<form><isindex>
+#errors
+#document
+| <html>
+| <head>
+| <body>
+| <form>