<template>
Markup kept aside, inert, waiting to be copied.
The content of a <template> is not rendered, downloads no images, runs no script and does not turn up in find-in-page. It sits in a separate fragment, reachable through the content property.
With shadowrootmode it gained a second life: the browser's own parser turns the template into a shadow root while reading the HTML, with no script involved at all.
<template id="linha-do-fichario">
<li class="ficha">
<span class="ficha__num"></span>
<span class="ficha__nome"></span>
</li>
</template>