(PHP 5, PHP 7, PHP 8)
DOMElement::setIdAttributeNS — Declares the attribute specified by local name and namespace URI to be of type ID
$namespace, string $qualifiedName, bool $isId): void
   Declares the attribute specified by qualifiedName and 
   namespace to be of type ID.
  
namespaceThe namespace URI of the attribute.
qualifiedName
       The local name of the attribute, as prefix:tagname.
      
isId
       Set it to true if you want name to be of type
       ID, false otherwise.
      
No value is returned.
DOM_NO_MODIFICATION_ALLOWED_ERRRaised if the node is readonly.
DOM_NOT_FOUND
       Raised if name is not an attribute of this element.