td.Xa:hover {outline: 1px solid #0F0} /* ascii */
td.Xl:hover {outline: 1px solid #0C0} /* latin1 */
td.Xz:hover {outline: 1px solid #F00} /* proposed */
+td.di-rare:hover {background: #BBB}
td.di-b:hover {background: #F88}
td.di-d:hover {background: #FF8}
td.di-prop:hover {background: #FC8}