Empty title (non-empty-title)
A non-empty <title> element is provided to describe the page’s topic or purpose.
Two title elements first empty:
This page has an empty <title> in the head and another invalid <title> inside the body. As a result, the page has no usable title.
<head>
<title></title>
</head>
<body>
<title>Title of the page.</title>
</body>