How can I add search/filer parameter to the end of about:config url? I have seen somewhere, but I forgot... I would like to add to bookmarks. For example, the browser.display.use_system_colors , because often switch true/false, and I hate retyping... It was something similar like this: "about:config?" and yet there was also "#" and perhaps even("search" or "q" or "query" and "="). Thanks!