<?php
add_filter('sanitize_title', 'remove_short_words');
function remove_short_words($slug) {
if (!is_admin()) return $slug;
$slug = explode('-', $slug);
foreach ($slug as $k => $word) {
if (strlen($word) < 3) {
unset($slug[$k]);
}
}
return implode('-', $slug);
}
?>