When customizing cookie settings, the following is shown under Strictly Necessary (click for bigger/sharper image):
These cookies are necessary for our website to function properly and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms or where they’re essential to provide you with a service you have requested. You cannot opt-out of these cookies. You can set your browser to block or alert you about these cookies, but if you do, some parts of the site will not then work. These cookies do not store any personally identifiable information.
While I don't have a problem when parts of the site will not then work, maybe we can phrase it better. Some options:
- Switch then and not: "if you do, some parts of the site will then not work".
- Cut then completely: "if you do, some parts of the site will not work".
- Ask our friends from English Language & Usage.
Personally I'd stick with 2. Keep things simple and make then go away.