Cookies

What a cookie is

A cookie is a small piece of text a website asks your browser to keep and send back on later visits. Browsers can also keep small notes for a single tab, which are gone when the tab is closed; we list those here too.

Strictly necessary: always on

These are needed for sign-in and for remembering your choice. They cannot be switched off here.

• Session cookie. Set when you sign in to the members' area and sent with each request, so the members' area knows it is you. It ends when you sign out or the session expires.
• csrftoken. A security token set alongside the session. It lets the members' area check that a change was really requested from your own browser.
• chx_consent. Records the choice you make on the cookie panel, so we do not ask again on every page. It lasts six months, after which we ask again. It holds the choice and its date, nothing about you.
• chx:login-redirect (kept for one tab, not a cookie). Notes the moment you were last sent to sign in, to stop the browser looping if sign-in fails. It is gone when you close the tab.
• Single sign-on. Sign-in happens on our identity service, which sets its own cookies on its own address to keep you signed in there. They are needed for sign-in and are not used for anything else.

Preferences: off unless you allow them

These make the site a little more convenient. Nothing breaks without them.

• sidebar_state. Remembers whether you left the side panel of the members' area open or closed. It lasts seven days and holds only whether the panel was open.

Measurement: off unless you allow it

Measurement shows us which pages are read and where visitors come from. Nothing below is set, and nothing is sent to Google, unless you allow it. Until you choose, and after a no, the measurement script is not loaded at all.

Measurement is switched on one site at a time. On a site where it is not switched on, allowing it sets only the note of where your visit came from, and nothing goes to Google.

If you allow it on a site where it is switched on, Google Analytics receives the pages of your visit, the site you came from, your approximate city, your device and browser, and a random number kept in a cookie. Allowing it also sends where your present visit came from. The pages you read before you said yes are not sent.

• _ga. Set by Google Analytics on this site's address. A random number that recognises your browser on a return visit. It lasts up to six months after your last visit and is removed when you refuse, withdraw or your choice expires.
• _ga_ followed by a code. Set by Google Analytics on this site's address. Keeps the state of your current visit. It lasts the same time and is removed the same way.
• chx_attr (kept in your browser's storage, not a cookie). Set by this site. Notes the source and campaign of your first and latest arrival, the site you came from and the page you landed on. The first arrival is kept for 90 days; all of it is removed with the cookies above. It is sent only with a message you send us.

What we do not use

We set no advertising cookies and no cookies from social networks or advertising networks. There is no such category to switch on.

Your choice

The first time you open a public page a small panel asks what to allow. "Only what is needed" keeps preferences and measurement off; "Allow all" turns both on. "More choices" shows a switch for each, and "Save" keeps a choice in between. The panel does not block the page, and until you choose, both stay off.

Everyone is asked first, wherever they are. The law of some countries lets a site measure visits unless the visitor objects; if we ever rely on that for a country, this page will name the country here before we do, and visitors from there will be told on every page how to turn measurement off.

You can change your mind at any time with "Cookie settings" at the foot of every public page. If you turn preferences off, the preference cookie is removed straight away. If you turn measurement off, its cookies and the note of where you came from are removed and the page is loaded again without the measurement script.

If you made your choice before measurement was added to the panel, your choice still stands and measurement is off. You can turn it on from "Cookie settings".

If your browser sends its own signal asking sites not to track it, measurement stays off and the panel says so.

Your browser can also block or delete cookies. If you block the necessary ones, you will not be able to sign in.

Changes

If we add or change a cookie we update this page first. If the change adds something you have not been asked about, the panel asks again. Questions: [email protected].