Cairn

Terms of Service

Last updated: April 27, 2026 · Draft v0.1

These Terms govern your use of Cairn ("the Service"). By using the Service, you agree to these Terms. The Japanese-language version is the authoritative text; in case of discrepancy, the Japanese text prevails.

1. Definitions

"Service"
The Cairn website and its writing/reading features.
"Entry"
A text of up to 50 characters submitted to the Service.
"User"
Any person who reads or writes via the Service.
"Operator"
The individual or entity operating the Service.

2. Nature of the Service

  1. The Service allows a User to submit one and only one Entry in their lifetime.
  2. Entries cannot be edited or deleted by the User after confirmation, except under the limited conditions in Section 11.
  3. Reading Entries is free and requires no account.

3. Eligibility to Write

  1. Users aged 16 or older may register and write directly.
  2. For persons aged 15 or younger, a parent or appropriate guardian (medical professional, NGO staff, etc.) may submit an Entry on their behalf via proxy registration.
  3. When writing, the User self-attests to their age and name as the minimum required information. The Operator may request production of identity documents after the fact where there is suspicion of fraud, duplicate registration, or other reasonable cause. Nothing in this paragraph precludes the Operator from moving, in future, to a stricter verification process including delegation to a certified KYC provider.
  4. To submit an Entry, a User must obtain one of the following:
    • Invitation code: a single-use, time-limited code issued by a User who has already completed their Entry.
    • Application lottery win: registration in the Operator's free application form, followed by winning the daily lottery drawing.

3-bis. Notebook Structure and Page Numbers

  1. Entries are compiled into annual "Books" (e.g., Cairn Book 2026).
  2. Upon confirmation, a sequential page number within that Book is assigned. Page numbers are not known to the User before confirmation.
  3. The page number and the content hash serve as permanent public identifiers.
  4. If an Entry is deleted under Section 11, its page number is not reused; the page is marked as "(retracted)" and remains blank.
  5. The Operator shall not issue Entries, page numbers, or content hashes as NFTs or any speculative financial instrument. However, the Operator does not intervene in third-party citation, transfer, or auction of such identifiers.

4. Fees and Payment

  1. Writing requires payment. Fees are set in two tiers based on the User's country:
    • Japan, United States, EU member states, United Kingdom, Canada, Australia, New Zealand, South Korea, Hong Kong, Taiwan, Singapore, Israel, GCC countries: $3.00
    • All other regions: $1.00
    The two-tier pricing reflects differences in local purchasing power so the burden of writing feels roughly the same wherever the User is.
  2. At checkout, Users may add an optional voluntary donation (+$0 / +$2 / +$5 / +$10 / +$25 / custom).
  3. Payment is processed via designated providers (e.g., Stripe).
  4. Due to the nature of digital content, no refunds are issued after confirmation. A cancellation UI is provided before final confirmation.
  5. The Operator pledges to donate 50% of net revenue (base fees minus payment processing fees, infrastructure costs, and taxes) to third-party public-interest organizations, with the remaining 50% allocated to operating costs and the Operator's compensation.
  6. For voluntary donation amounts added at checkout, 100% (less payment processing fees) is donated.
  7. Donation recipients are selected by the Operator based on safety, transparency, and alignment with the Service's purpose. The initial recipient set is:
    • Médecins Sans Frontières (MSF) — emergency medical care in conflict and underserved areas
    • UNHCR — protection of displaced people
    • Internet Archive — long-term preservation of human record
    • Wikimedia Foundation — continued access to free knowledge
    The recipient set is reviewed every six months; any change will be announced in advance via these Terms and the Operator's transparency report.
  8. The Operator publishes a transparency report every six months, covering donation amounts, recipients, and an operating-cost summary, and remits donations to recipients on the same cadence.
  9. The Operator does not offer any free tier, sponsored slot, or fee waiver. Writing fees are always borne by the User.

5. Publicly Displayed Information

After an Entry is confirmed, the following becomes public:

Identity documents, contact details, and payment information are never public.

6. Intellectual Property

  1. Copyright in each Entry remains with the User.
  2. The User grants the Operator a worldwide, perpetual, royalty-free license to publish, reproduce, and distribute the Entry.
  3. If the Service is shut down, the Operator will make reasonable efforts to preserve Entries in a permanently accessible form (e.g., IPFS, donation to national libraries).

7. Prohibited Content

Entries must not contain:

  1. Disclosure of others' personal information
  2. Defamation or insult of a specific person or group
  3. Incitement of hatred toward a specific person or group
  4. Incitement or facilitation of illegal acts
  5. Child sexual exploitation material
  6. Glorification or incitement of terrorism
  7. Commercial advertising or spam
  8. Unauthorized reproduction of copyrighted works
  9. Meaningless strings or machine-generated content
  10. Any content the Operator reasonably deems contrary to public morals

8. Handling of Identity Verification Data

  1. Under current operations, the Operator does not collect ID documents before writing as a default (see Section 3.3). Any documents a User provides in response to a later request from the Operator are encrypted at rest and never made public.
  2. Such documents are not disclosed to third parties except: (a) in response to valid legal requests, (b) court orders, or (c) at the User's own request.
  3. The Operator may in future delegate verification to certified KYC providers (e.g., Onfido, Persona). Any such delegation will be disclosed in the Privacy Policy in advance, together with the consent mechanism required.

9. Proof of Authorship

  1. A SHA-256 hash of the Entry is generated and publicly displayed upon confirmation.
  2. Users may later request the Operator to certify their authorship using their original credentials.
  3. Upon valid request, the Operator issues a "Certificate of Authorship."

10. Proxy Registration for Minors

  1. Guardians may submit Entries on behalf of children aged 15 or younger.
  2. For proxy registration, the guardian and the child's identity are provided by self-attestation. The Operator may request production of supporting documents (birth certificate, passport, family registry, etc.) where it considers this necessary.
  3. The public display will include: "Words of a child, [country] [year of birth], submitted by [guardian name]."
  4. A child registered as a minor may make their own Entry in adulthood as an exception to the once-in-a-lifetime rule.

11. Deletion of Entries

The Operator may delete an Entry only in the following cases:

  1. The Entry reasonably violates Section 7.
  2. In response to a valid court order or legitimate law enforcement request.
  3. The User designated post-mortem deletion during their lifetime, and death has been verified.
  4. The User requests deletion and the Operator recognizes special circumstances (limited to once per person, additional fee $100).

12. Disclaimers

  1. The Service is provided "as is." The Operator makes no warranty of fitness, accuracy, or continuity.
  2. The Operator is not liable for Entry content. Disputes regarding Entries are the responsibility of the writer.
  3. The Operator is not liable for temporary or permanent service interruption due to server failure, natural disaster, war, or censorship. Donation obligations under Section 4 remain.

13. Changes to These Terms

These Terms may change without notice. Updated Terms take effect upon posting. Existing Entries are governed by the Terms in effect at the time of submission.

14. Governing Law and Jurisdiction

  1. These Terms are governed by the laws of Japan.
  2. Disputes shall be subject to the exclusive jurisdiction of the Tokyo District Court as the court of first instance.

15. Relationship Between Language Versions

The Japanese-language version is authoritative. Other language versions are provided for reference; in case of discrepancy, the Japanese text prevails.