HTMLAreaElement: relList property

The HTMLAreaElement.relList read-only property reflects the rel attribute. It is a live DOMTokenList containing the set of link types indicating the relationship between the resource represented by the <area> element and the current document.

The property itself is read-only, meaning you can't substitute the DOMTokenList by another one, but the content of the returned list can be changed.

const areas = document.getElementsByTagName("area");
const length = areas.length;

for (const area of areas) {
  console.log("New area found.");
  area.relList.forEach((relValue) => {
    console.log(relValue);
  });
}