Although there are "open in back" settings for links, bookmarks, and context menu searches, there does not seem to be one for the URL bar drop-down. I can understand why not, since you nearly always are using the address bar to immediately access something. I don't know whether there is any plan to add the option.

Are you opening results from bookmark and history matches, or your top sites list?

It still works for me if I hold Ctrl+Shift and click an item in the drop-down list.
Holding Shift additionally (Ctrl+Shift) reverses the "When you open a link in a new tab, switch to it immediately" setting to open the tab in the background (doesn't seem to be necessary).

@jscher2000, the content of my URL bar dropdown is a mix of history entries and bookmark entries (though the latter might also come as history entries). For neither it works.

@cor-el, I tried that with some success. It opens the the URL in a tab in the background. However, this seems to be completely counter-intuitive and different to the behavior anywhere else in Firefox :( : When I Ctrl+Shift click (left, middle), I open the URL in a new tab in the background if it is in the URL bar dropdown. When I do the same on a URL anywhere else, it just opens in a new tab and gets focus.

Also, what is missing, is that this can be done without a keyboard (very important!) like for regular links. And possibly to not close the URL bar dropdown after clicking. Otherwise you can't right click on more links to open all of them.

jscher2000 said

Are you opening results from bookmark and history matches, or your top sites list?

@jscher2000, the content of my URL bar dropdown is a mix of history entries and bookmark entries (though the latter might also come as history entries). For neither it works.

What I meant was are you trying to open items that matched what you typed into the address bar, which are only convenient to access through the address bar drop-down, or items that appear on your Top Sites / frequently visited URLs list when you click in the address bar before you start typing any text, a list which could be accessed in other ways.

shiin said

jscher2000 said

Are you opening results from bookmark and history matches, or your top sites list?

@jscher2000, the content of my URL bar dropdown is a mix of history entries and bookmark entries (though the latter might also come as history entries). For neither it works.

What I meant was are you trying to open items that matched what you typed into the address bar, which are only convenient to access through the address bar drop-down, or items that appear on your Top Sites / frequently visited URLs list when you click in the address bar before you start typing any text, a list which could be accessed in other ways.

I am most often trying to open the latter in this way. I don't know of another convenient way to access them, though. Only sometimes (rarely), I am trying to open the former in this way.

jscher2000 said

What I meant was are you trying to open items that matched what you typed into the address bar, which are only convenient to access through the address bar drop-down, or items that appear on your Top Sites / frequently visited URLs list when you click in the address bar before you start typing any text, a list which could be accessed in other ways.

I am most often trying to open the latter in this way. I don't know of another convenient way to access them, though. Only sometimes (rarely), I am trying to open the former in this way.

Well, at the risk of sound self-promoting, I made an add-on for that, and it has an option to always open items you click in a new tab AND in the background.

https://addons.mozilla.org/firefox/addon/show-history-top-sites-button/

I mean, in some sense, we're reinventing bookmarks here, but we tend to use what we're used to. ;-)