Site information

Privacy

This edition has no account system, advertising trackers, embedded third-party media or contact form. Fonts and site scripts are served from this website. Google Analytics loads only after you choose Allow analytics. Declining keeps the Google tag unloaded.

Optional Google Analytics

If you allow analytics, Google Analytics 4 receives page and usage events, browser/device information and technical request data. It uses first-party analytics cookies for up to 180 days. We remove query strings and fragments from the page address and referrer sent by our tag configuration. Google signals and advertising personalisation are disabled in our tag configuration. Read Google’s privacy policy and how Google Analytics handles data.

Your choice is stored in this browser for 180 days. Use Analytics settings in the footer to change it; declining after acceptance stops the tag and removes this site’s analytics cookies. Do Not Track and Global Privacy Control prevent loading. Page checks marked with the qa parameter do not load analytics. Reports cover consenting visits and do not measure every reader.

Worksheet interactions

Worksheet ticks exist only in the current page. They are not sent to us or retained in browser storage. Printing uses your browser’s print facility. Do not enter personal or confidential information into printed notes unless your own handling process permits it.

Server requests

The hosting server can process request information such as IP address, requested URL, time, browser information and response status to deliver pages and investigate operational problems. Access is restricted to authorised administration. Server logs are rotated daily when in use. Up to 14 rotated logs are retained in addition to the current log.

External resources

Following an external reference opens another organisation’s website, which has its own privacy practices. We do not control that service.

Edition dated 4 November 2026.