PAPER THREE · LEGAL

Privacy policy

Effective 30 September 2026

This policy explains the information handled by paper3physics.com. The website is operated by ZHAO JIFENG, an individual in mainland China. For privacy requests, email jintlgs@163.com.

Information we handle

• Learning progress: completed and saved lessons are stored in your browser on your device. We do not receive them through a user account.
• Feedback: if you send feedback, we store your message, the page it concerns, the time, and an optional reply email in a private Cloudflare inbox. We use a temporary one-way hash of the connection address to limit repeated submissions.
• Purchases and access: Waffo Pancake handles checkout and payment details. After a confirmed payment, we receive the order status, order identifier and buyer email for access and support. We store a course entitlement, a hashed recovery-key lookup and a short-lived checkout record in Cloudflare. The recovery key is also held in that checkout record for up to seven days so it can be shown after payment. An essential browser cookie keeps your paid access session. We do not receive or store complete payment-card numbers.
• Technical delivery data: Cloudflare processes connection information, such as IP address and browser request details, to deliver and protect the site. We do not use advertising pixels or third-party analytics on this website.

Why we use it

We use purchase information to deliver the course and respond to access or refund issues; feedback and optional email to read and, if requested, reply; and technical data to operate and protect the website. We do not sell personal information or send marketing email from information collected here.

Cookies and local storage

The paid course uses a secure, HTTP-only access cookie lasting up to 180 days and a temporary checkout cookie lasting up to 7 days. The private feedback inbox uses an administrator session cookie. These are necessary for their respective functions. Lesson progress and saved lessons use browser local storage. You can clear cookies and local storage in your browser, but doing so may sign you out or remove progress from that device. There are no advertising or analytics cookies on this site.

Storage periods

Feedback and an optional reply address are deleted automatically after 90 days. The anti-spam hash expires after 60 seconds. Pending checkout records expire after 7 days. Your browser keeps local progress until you clear it. We keep the minimal order and access records while paid access remains active; after access ends, we delete those records within 24 months, unless a longer period is needed for a legal obligation or an active dispute. Waffo retains its own transaction records under its separate policy.

Service providers and international handling

Cloudflare hosts the website and private storage. Waffo Pancake is the merchant of record and handles payment information under its own privacy policy. These providers may process information in countries outside your own. Their policies explain their handling and applicable transfer protections. We do not disclose your information to advertisers.

Your choices and requests

You can remove progress from your device using browser controls. To ask for a copy, correction or deletion of information we hold, or to raise a privacy concern, email jintlgs@163.com. Please include enough information for us to identify the relevant feedback or order; we may need to verify a purchase before changing access records. We will respond in line with applicable law. Waffo handles requests about payment information it holds directly.

Children

The website is intended for students aged 16 or older. We do not knowingly seek personal information from children under 16. If a parent or guardian believes a younger child sent us information, contact jintlgs@163.com so we can remove it. Students who are minors should ask a parent or guardian to make and manage purchases.

Changes

We will update the effective date when this policy changes and post material changes on the website. For questions or requests, email jintlgs@163.com. See also our Terms of Service.