From this version on, I don't care about cookies browser extension notifies websites about which cookies you allow them to install on your computer.
By default, you allow them to install required cookies, that is, cookies needed for the website to work properly. You don't allow them to install other cookies (in example, cookies related to ads, marketing, analytics...) by default. You can change that in extension's options.
By knowing which permission you gave them, websites can skip displaying the cookie warning if they want and act according to the given permission. As a result, you will be bothered by cookie warnings even less then before.
If your favorite website displays a cookie warning which can't be easily hidden nor accepted with "I don't care about cookies" extension, please ask its administrators to check for the permission you give them and to stop displaying the cookie warning to you.
Implementation instructions for web developers can be found here.