This rule checks that the specified child elements are present inside the specified parent elements.
Noncompliant code example
Given a parent/child combination of <head>/<title>:
<html>
<head>
</head> <!-- Noncompliant; no title element -->
<body>
...
Compliant solution
<html>
<head>
<title>My Page</title>
</head>
<body>
...
