I noticed in Firefox 42 that there is a new TYPE_EMBED as distinct from TYPE_OBJECT (and the tracking bug also mentioned the long-deprecated APPLET), and that SUBDOCUMENT was split into FRAME and IFRAME (and maybe IMPORT for HTML Imports, I know that was mentioned in the tracking bug): https://developer.mozilla.org/en-US/Firefox/Releases/42#nsIContentP...

I realize that you have probably already seen this change, because Firefox 42 Nightly builds started appearing months ago, but I'm surprised to see all the types that have been added to nsIContentPolicy over the years: https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Referen...

I wonder whether AdBlock for Firefox will support new filter syntax to specially handle these new content types, or maybe just (for consistency with the other platforms) merge them with the existing request-type selectors, like mapping FRAME, IFRAME, and IMPORT to subdocument, EMBED to object, IMAGESET to image, FETCH and BEACON to xmlhttprequest, etc. (or maybe some of these are just mapped to other).