Privacy policy

QFT.org is operated by Jie Ren. The site has no registration, reader accounts, or contact forms.

Effective date: 30 September 2026.

Visits and analytics

Cloudflare delivers and protects this site, processing request information such as IP addresses for delivery and security. Processing may occur outside your country; see the Cloudflare Privacy Policy.

QFT.org uses Cloudflare Web Analytics with the Global setting to understand site use and performance across all regions. It collects page visits, referrers, browser and device categories, and performance measurements. Cloudflare states that its analytics does not use cookies or fingerprint visitors; see Cloudflare Web Analytics. QFT.org does not use Google Analytics or advertising trackers.

Browser preferences

Search runs in your browser. Search and filter URLs may contain your query. Theme and sidebar preferences are stored in your browser and can be cleared through its site-data controls. You can also block the analytics beacon with a browser content blocker.

Email and privacy requests

Send feedback or privacy questions to renphysics@qft.org. Your email address and message are used to handle your correspondence. Email passes through Cloudflare Email Routing and is stored in a Microsoft-hosted mailbox until manually deleted, subject to the providers’ policies, including the Microsoft Privacy Statement. Use the same address to request access, correction, or deletion of your correspondence.