Untitled

dabblet.css

a { color: red; }
a[rel='friend'] { color: green; }
a[rel~='friend'] { color: blue; }
a[lang|='es'] { color: yellow; }

dabblet.html

<ul>
        <li><a href="" lang="en-GB" rel="friend met">Peter</a></li>
        <li><a href="" lang="es-ES" rel="friend">Pedro</a></li>
        <li><a href="" lang="es-MX" rel="contact">Pancho</a></li>
    </ul>

settings.json

{"view":"split","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}