This shows which elements change in the DOM when nested.
<$[data1] id=x><$[data1]></$[data1]></$[data1]>const element = document.getElementById('x');0x0D
if(element && !element.querySelector('$[data1]')) {0x0D
log('$[data1]');0x0D
}<a id=x><a></a></a><area id=x><area></area></area><base id=x><base></base></base><br id=x><br></br></br><button id=x><button></button></button><dd id=x><dd></dd></dd><dt id=x><dt></dt></dt><embed id=x><embed></embed></embed><form id=x><form></form></form><h1 id=x><h1></h1></h1><hr id=x><hr></hr></hr><iframe id=x><iframe></iframe></iframe><img id=x><img></img></img><input id=x><input></input></input><li id=x><li></li></li><link id=x><link></link></link><meta id=x><meta></meta></meta><nobr id=x><nobr></nobr></nobr><noembed id=x><noembed></noembed></noembed><noframes id=x><noframes></noframes></noframes>