This vector shows what Named HTML entities that can be closed with !.
<img src=data: onerror="`&$[data1]!x`==`&$[data1];!x`?log('$[data1]'):0"><img src=data: onerror="`ª!x`==`ª!x`?alert('ordf'):0"><img src=data: onerror="`â!x`==`â!x`?alert('acirc'):0"><img src=data: onerror="`¥!x`==`¥!x`?alert('yen'):0"><img src=data: onerror="`û!x`==`û!x`?alert('ucirc'):0"><img src=data: onerror="`¨!x`==`¨!x`?alert('uml'):0"><img src=data: onerror="`Ñ!x`==`Ñ!x`?alert('Ntilde'):0"><img src=data: onerror="`æ!x`==`æ!x`?alert('aelig'):0"><img src=data: onerror="`Î!x`==`Î!x`?alert('Icirc'):0"><img src=data: onerror="`þ!x`==`þ!x`?alert('thorn'):0"><img src=data: onerror="`ê!x`==`ê!x`?alert('ecirc'):0"><img src=data: onerror="`<!x`==`<!x`?alert('lt'):0"><img src=data: onerror="`ï!x`==`ï!x`?alert('iuml'):0"><img src=data: onerror="`¯!x`==`¯!x`?alert('macr'):0"><img src=data: onerror="`ô!x`==`ô!x`?alert('ocirc'):0"><img src=data: onerror="`à!x`==`à!x`?alert('agrave'):0"><img src=data: onerror="`Ô!x`==`Ô!x`?alert('Ocirc'):0"><img src=data: onerror="`Ü!x`==`Ü!x`?alert('Uuml'):0"><img src=data: onerror="`£!x`==`£!x`?alert('pound'):0"><img src=data: onerror="`ö!x`==`ö!x`?alert('ouml'):0"><img src=data: onerror="`ð!x`==`ð!x`?alert('eth'):0">