Although this page seems to load file, I get an error from NU HTML checker. Not sure how to clear the error, because it seems everything in the body would of course be a child of the XHTML body element.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>How About Them Apples?</title>
<meta charset="utf-8" />
<link href="apples.css" rel="stylesheet" type="text/css" />
</head>
<body>
<apples xmlns:apls="https://www.dole.com/en/products/apples">
<apls:apple>
<apls:name>Red Delicious</apls:name>
<apls:color>Red</apls:color>
</apls:apple>
<apls:apple>
<apls:name>Golden Delicious</apls:name>
<apls:color>Yellow</apls:color>
</apls:apple>
</apples>
</body>
</html>