I'm not aware of any consolidated list.

The MozillaZine site has pages for many, many of the individual settings. If you right-click a preference > Copy name, and then search it, you are likely to find one of those pages in the top results. Alternately, you can install their search plugin.

For example:

• http://kb.mozillazine.org/About:config
• http://kb.mozillazine.org/Permissions.default.image

If you don't find a page in MozillaZine, and you don't mind poking around, you often can find comments in the Firefox source code explaining the different values.

The DXR site is probably the fastest place to do that kind of search for a preference name, but there isn't a rule as to which file will have the best detail on it when you get multiple results.

http://dxr.mozilla.org/

There are a lot of articles about the about:config page on the mozillaZine knowledge base website.

• http://kb.mozillazine.org/About:config_entries
• http://kb.mozillazine.org/Category:Preferences

There are also useful comments in the Firefox source code.

• resource:///defaults/preferences/firefox.js
• resource:///defaults/preferences/firefox-branding.js
• resource:///defaults/preferences/firefox-l10n.js
• resource://gre/greprefs.js

• http://mxr.mozilla.org/mozilla-release/source/modules/libpref/init/all.js
• http://mxr.mozilla.org/mozilla-release/source/browser/app/profile/firefox.js

Sometimes it may take searching in the general issues tracker bugzilla.mozilla.org to even find information on what a preference is and when it was put in.

See this extension: https://addons.mozilla.org/en-US/firefox/addon/config-descriptions/

"This extension provides a quick way to view the information about preferences that is already shipped with your browser. For more detail and information about other preferences without source comments, you'll still need to look them up online."

Unfortunately, too many "shipped" prefs don't have source comments that explain what they are about, which is what this extension uses for the Source Comment field in about:config.

Thanks-this partially solved my issue, and though infrequent the extra information is very interesting. I wanted to find a way to force firefox to open new windows in the background. With the extension you suggested loaded, I found this setting and options: browser.link.open_newwindow;1 with the comment handle links targeting new windows 1=current window/tab, 2=new window, 3=new tab in most recent window the default was 2, I changed it to 1. Thanks again to all for your suggestions, some of the links are fascinating. Jeff

While opening a new window in firefox I still get it 'on top', but now if I 'open link in browser' from thunderbird, thunderbird still stays on top. I tend to go through mail and open links and it's annoying to repeatedly reselect thunderbird. Jeff

Note that you should find this in Options/Preferences > Tabs ("New pages should be opened in": "a new tab/window"), only the current tab setting needs to be done via about:config.

See also:

• http://kb.mozillazine.org/browser.link.open_newwindow
• 1: current tab; 2:new window; 3:new tab;

For links opened via JavaScript you can look at this pref:

• http://kb.mozillazine.org/browser.link.open_newwindow.restriction

Check this out: http://kb.mozillazine.org/About:config_entries

FredMcD said

Check this out: http://kb.mozillazine.org/About:config_entries

Already posted in third reply in thread by cor-el . ;)