issue_comments: 1017975322

Turns out that banner is something that ReadTheDocs implemented - I found it using GitHub code search, it's produced by this piece of JavaScript: https://github.com/readthedocs/readthedocs.org/blob/0852d7c10d725d954d3e9a93513171baa1116d9f/readthedocs/core/static-src/core/js/doc-embed/version-compare.js#L13-L21

```javascript function init(data) { var rtd = rtddata.get();

/// Out of date message

if (data.is_highest) {
    return;
}

var currentURL = window.location.pathname.replace(rtd['version'], data.slug);
var warning = $(
    '<div class="admonition warning"> ' +
    '<p class="first admonition-title">Note</p> ' +
    '<p class="last"> ' +
    'You are not reading the most recent version of this documentation. ' +
    '<a href="#"></a> is the latest version available.' +
    '</p>' +
    '</div>');

warning
  .find('a')
  .attr('href', currentURL)
  .text(data.slug);

var body = $("div.body");
if (!body.length) {
    body = $("div.document");
}
body.prepend(warning);

} ```

And here's where that module is called from the rest of their code: https://github.com/readthedocs/readthedocs.org/blob/bc3e147770e5740314a8e8c33fec5d111c850498/readthedocs/core/static-src/core/js/doc-embed/footer.js#L66-L86