Cookies: what gets stored here, and how to say no

1

What one is, and what one is not

What a cookie cannot do is worth saying as well, because the word frightens people more than it should. It is a short piece of text and not a program. It cannot read a disk, open a file or run anything, and a browser returns it only to whoever set it.

Two kinds exist in practice and the line between them matters. One kind is needed to serve a page at all or to remember a choice a reader has made. Everything else is optional, which on a site of published sums means almost all of it.

2

What a site of sums actually needs

There is nothing here to log into, so nothing here needs a session to keep somebody logged in. What does need storing is a choice: a banner recording a preference has to put that preference somewhere, or it would be asked again on every page a reader opens.

A banner exists because the optional kind needs asking about first. Answering it costs one click and the answer then has to be stored, which is itself the slightly circular reason a preference cookie survives a refusal of everything else.

The same reasoning covers anything else a browser can be asked to keep, local storage included. Whatever the mechanism, the test applied here is whether a page of arithmetic needs it, and the answer is usually that it does not.

Measured against that test, the honest summary is short. A reader who blocks everything optional loses nothing at all here: no sum disappears, no table collapses, no citation goes missing. That is not a concession so much as a consequence of publishing arithmetic rather than selling attention.

3

What is not listed on this page

Names and lifetimes of whatever gets set are not listed on this page. A list printed once goes stale quietly, which is the worst way for a list to go wrong, so the current one is available on request instead.

No measurement company is named here either, for the same reason the privacy page names none. A vendor written down from memory is a fabricated fact about somebody else’s business, and the rule against that is the rule this whole site runs on, which is set out at who publishes this.

4

Refusing, and clearing out what is there

Anything not needed to serve a page can be refused outright, and refusing it costs a reader nothing here. None of the arithmetic depends on knowing who is reading it, so a declined measurement cookie changes nothing on the page.

Clearing what has already been stored is done through the browser rather than through this site, and every major browser carries the setting. Clearing it also clears any stored preference, which is why a banner reappears afterwards.

Cookies set by somebody else’s site, after a commercial link has been followed, are that site’s business and outside the reach of anything written here. What the link itself is for is explained at how this site is paid.

5

Asking, objecting and changes

Objecting to any of this, or asking what is currently set, goes through the contact page. A list that is accurate on the day it is asked for beats a list printed here and quietly left to rot.

A revision figure sits in the reference line above, and it steps forward whenever this wording is altered. The wider question of what a visit leaves behind at all is on the privacy page, and what a message on either subject should contain is at write to us.