To see all the History and Cookie options, select: Tools > Options > Privacy > History: Firefox will: "Use custom settings for history"
See Settings for privacy, browsing history and do-not-track

• Let all cookies expire when you close Firefox.
• Tools > Options > Privacy > Cookies: "Keep until": "I close Firefox"
• Make an Allow exception for the ones that you want to keep.
• Tools > Options > Privacy > Cookies: "Exceptions"

You can inspect and modify the permissions for the domain in the current tab in "Tools > Page Info > Permissions"
Make sure that you do not use Delete browsing, search and download history on Firefox to clear the "Cookies" and the "Site Preferences" (Site Preferences includes the cookie exceptions)
Clearing cookies will remove all specified (selected) cookies including cookies that have an allow exception.

Sorry, but I can not see how this helps at all. Maybe I don't understand the instructions, But I tried the above and didn't get what I wanted.

The allow exceptions also get deleted when I close Firefox - if I select keep until I close Firefox. The allow exceptions seem to be to allow cookies on specified sites when cookies are disabled.

What I want is to protect specified cookies from being deleted.

It's strange, but when viewing cookies you have 2 options -

Delete one at a time, or Delete all.

You can't even use the shift or control keys to select a range. I must be missing something obvious.

aj

You're right, @corel-el's answer doesn't help (nor did it with the similar post here titled "clear cookies on exit Except for listed Exceptions" at https://support.mozilla.com/en-US/que.../757652). See my post there for a Windows workaround using a free utility called ccleaner which I'm still having to use with Firefox v3.6.13.

This is a problem that was introduced sometime in the several month because cookies marked "Allow" used to work to keep those you wanted from being deleted.

Update

I just found this Mozilla extension called "CookieCuller" that might help it's at https://addons.mozilla.org/en-US/firefox/addon/82 and has a "Cookie Keep List".

You can select more than one cookie in the Cooke Manager (Shift + cursor Down) and press the Delete key or click Remove to remove selected cookies.

Make sure that you do not use Delete browsing, search and download history on Firefox to clear the "Cookies" and the "Site Preferences"
Clearing "Site Preferences" clears all cookies, images, pop-up windows, software installation, and password exceptions.

Cookies are only protected within the CookieCuller extension, so do not use "Clear Recent History", but let the cookies expire if you close Firefox and protect the ones that you wish to keep.

@cor-el's response was actually spot-on. He just should have realized that you would have tried that ;) and so he forgot one thing...

For some reason, the cookie exception list is considered to be a "site preference" - so If you have Firefox set to delete "site preferences" (among the other options) when you exit, for some reason it deletes all of these exceptions... so everything gets deleted. I have it set not to delete "site preferences" but to delete cookies, etc. This way it deletes all cookies and leaves the exception list as is. It's a completely nonsensical way of implementing this feature, if you ask me. And what else is considered a "site preference"?? Oh well ;)