jQuery( "[attribute|='value']" )
/* Description: Selects elements that
have the specified attribute with a value either equal to a given string or
starting with that string followed by a hyphen (-). */
<body>
<a href="example.html" hreflang="en">Some text</a> <!-- will select this -->
<a href="example.html" hreflang="en-UK">Some other text</a> <!-- will select this -->
<a href="example.html" hreflang="english">will not be outlined</a> <!-- not this -->
<script>
$( "a[hreflang|='en']" ).css( "border", "3px dotted green" );
</script>
</body>
</html>