HTMLElement - Web APIs
htmlelement.dropzone read only returns a domsettabletokenlist reflecting the dropzone global attribute and describing the behavior of the element regarding a drop operation.
... htmlelement.itemtype read only returns a domsettabletokenlist… htmlelement.itemid is a domstring representing the item id.
... htmlelement.itemref read only returns a domsettabletokenlist… htmlelement.itemprop read only returns a domsettabletokenlist… htmlelement.itemvalue returns a object representing the item value.

HTMLTableCellElement - Web APIs
htmltablecellelement.headers read only is a domsettabletokenlist describing a list of id of <th> elements that represents headers associated with the cell.
... the headers property is now read-only and contains a domsettabletokenlist rather than a mere domstring.

Document Object Model (DOM) - Web APIs
it is uncertain whether some may be reintroduced in the future or not, but for the time being they should be considered obsolete and should be avoided: documenttouch domconfiguration domerrorhandler domimplementationlist domimplementationregistry domimplementationsource domlocator domobject domsettabletokenlist domuserdata elementtraversal entity entityreference namelist notation typeinfo userdatahandler html dom a document containing html is described using the document interface, which is extended by the html specification to include various html-specific features.

HTMLIFrameElement - Web APIs
htmliframeelement.sandbox is a domsettabletokenlist that reflects the sandbox html attribute, indicating extra restrictions on the behavior of the nested content.

HTMLLinkElement - Web APIs
htmllinkelement.sizes read only is a domsettabletokenlist that reflects the sizes html attribute, as a list of tokens.