a.nn { text-decoration: none !important; }
a.nn:hover { text-decoration: none !important; }

a.ny { text-decoration: none !important; }
a.ny:hover { text-decoration: underline !important; }

a.yn { text-decoration: underline !important; }
a.yn:hover { text-decoration: none !important; }

a.yy { text-decoration: underline !important; }
a.yy:hover { text-decoration: underline !important; }