HTMLLinkElement.relList
  The HTMLLinkElement.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
  <link> element and the current document.
  The property itself is read-only, meaning you can substitute the
  DOMTokenList by another one, but the content of the returned list can be
  changed.
Syntax
var relstr = linkElt.relList;
Example
var links = document.getElementsByTagName("link");
var length = links.length;
for (var i = 0; i < length; i++) {
  var list = links[i].relList;
  var listLength = list.length;
  console.log("New link found.");
  for (var j = 0; j < listLength; j++) {
    console.log(list[j]);
  }
}
Specifications
| Specification | 
|---|
| HTML Standard  # dom-link-rellist  | 
Browser compatibility
BCD tables only load in the browser
See also
- 
    The equivalent property on 
<a>and<area>,HTMLAnchorElement.relListandHTMLAreaElement.relList. - 
    The very same list but as a space-separated tokens in a 
DOMString:HTMLLinkElement.rel