<html>
<head>
<title>CSS content test</title>
<style>
H1:before {
  content: attr(myAttr) " Chapter: "
}
H2:before {
  content: attr(myAttr) "Chapter: "
}
H3:before {
  content: "Chapter " attr(myAttr) ": "
}
H4:before {
  content: "Chapter: " attr(myAttr)
}
</style>
</head>
<body>
<h1 myAttr="First">TEST 1</h1>
Should read: "First Chapter: TEST 1"
<h2>TEST 2</h2>
Should read: "Chapter: TEST 2"
<h3 myAttr="One">TEST 3</h3>
Should read: "Chapter One: TEST 3"
<h4>TEST 4</h4>
Should read: "Chapter: TEST 4"
</body>