a:after {
content: " (" attr(href) ")";
}<!DOCTYPE html>
<html>
<head>
<style>
a:after {content: "Nazione: " attr(data-flag);}
</style>
</head>
<body>
<h1>The attr() Function</h1>
<p><a href="https://www.w3schools.com" data-flag="Italia"></a></p>
<p><a href="https://www.w3schools.com/html/" data-flag="Repubblica Francese"></a></p>
</body>
</html>