The HTMLIFrameElement.referrerPolicy property reflect the HTML referrer attribute of the <iframe> element defining which referrer is sent when fetching the resource.
The HTML Browser API is an extension of the HTML <iframe> element that allows web apps to implement browsers or browser-like applications. It currently works in (privileged) chrome code on Firefox desktop (version 47 and above) and privileged and certified apps on B2G/Firefox OS.
The executeScript() method of the HTMLIFrameElement interface allows a specified script to be executed against a page loaded in the browser <iframe>.
The findAll() method of the HTMLIFrameElement searches for a string in a browser <iframe>'s text content; if found, the first instance of the string relative to the caret position will be highlighted.
The findNext() method of the HTMLIFrameElement highlights the next or previous instance of a search result after a findAll() search has been carried out.