MediaWiki:Common.css

/* CSS placed here will be applied to all skins */
.jstree-leaf a[title="Deutsche Texte"]:after {
content: " 🇩🇪";
} 
.jstree-leaf a[title="English Texts"]:after {
content: " 🇬🇧";
} 
.jstree-leaf a[title="Teksty Ponical"]:after {
content: " 🇵🇱";
}