Proposals and non-standard elements

<fencedframe width="640" height="320"></fencedframe>

const frameConfig = await navigator.runAdAuction({
  // … auction configuration
  resolveToConfig: true,
});

const frame = document.querySelector("fencedframe");
frame.config = frameConfig;

<geolocation>
  <button id="fallback">Use location</button>
</geolocation>
<p id="output"></p>

const outputElem = document.querySelector("#output");

if (typeof HTMLGeolocationElement === "function") {
  const geo = document.querySelector("geolocation");
  geo.addEventListener("location", () => {
    if (geo.position) {
      outputElem.textContent += `(${geo.position.coords.latitude},${geo.position.coords.longitude}), `;
    } else if (geo.error) {
      outputElem.textContent += `${geo.error.message}, `;
    }
  });
} else {
  const fallback = document.querySelector("#fallback");
  fallback.addEventListener("click", () => {
    navigator.geolocation.getCurrentPosition(
      (position) => {
        outputElem.textContent += `(${position.coords.latitude}, ${position.coords.longitude}), `;
      },
      (error) => {
        outputElem.textContent += `${error.message}, `;
      },
    );
  });
}