Which section for tweak?
Where can I add browser.display.show_image_placeholders=false tweak? I find it useful.
Since June 2013 its possible to use h.264 in firefox.
It uses the gstreamer lib. I thought it would be a neat tweak. Only thing to do is set "media.gstreamer.enabled" in about:config to true.
This isnt bulletproof, therefor i havent added it to the wiki myself.
Maybe Pageadmin decides about it.