# PSSN v1.0 — Pan-African Sovereign Serial Number

**Registry implementation note (2026-11-01):** This is the existing sovereign serial identifier design, implemented in the Pan-African Index v2 prototype. It is distinct from the official ISSN scheme. The Pan-African Index does not assign or claim official ISSNs.

## Scope
PSSN identifies an ongoing serial publication: journals, newsletters, ongoing proceedings series, book series and other continuing publications. It identifies the continuing publication, not its individual articles or the legal person operating it. An article receives a separate PAI UID and may link to the parent serial record.

## Structure
`P-CC-YYYY-NNNN-C`

- `P`: namespace marker for sovereign serials.
- `CC`: ISO 3166-1 alpha-2 country supplied by the registrant, subject to verification.
- `YYYY`: UTC year of PSSN issuance, not publication year.
- `NNNN`: four-character uppercase base-36 allocated sequence within `P / country / year`.
- `C`: check character, 0–9 or X, computed as below.

The sequence starts at `0001`. It is allocated transactionally and never reused. The identifier remains stable across title, host or publisher changes. The registry's universal PAI UID is the canonical record key and is separate from the PSSN.

## Check algorithm
1. Remove the hyphens from the 12-character core (do not include the check character).
2. Replace digits by 0–9, uppercase letters A–Z by 10–35.
3. Starting from the right, multiply character values by weights `2, 3, 4, 5, 6, 7`, repeating as necessary.
4. Let `r = weighted_sum mod 11`; `c = (11 - r) mod 11`.
5. Encode `c = 10` as `X`, otherwise as the digit.

Regex: `^P-[A-Z]{2}-[0-9]{4}-[0-9A-Z]{4}-[0-9X]$`. Passing the check digit validates syntax only, not ownership, authenticity or trust.

## Authority and governance
A publisher key may register a new serial and receive a syntactically valid PSSN instantly. The resulting record is registered and publicly discoverable immediately. Staff may maintain supporting provenance internally without changing the record’s public standing. Disputes, corrections, duplication and appeals have separate workflows. Confirmed fraudulent claims are addressed through a documented decision process; identity history must not disappear silently.

An existing ISSN / ISSN-L / DOI can be associated as a *separately sourced external identifier* subject to checksum, namespace and duplicate checks. The registry cannot issue an ISSN or DOI merely because a PSSN exists.

## Status
Operational in the PAI v2 code release. Institutional recognition, delegated issuing authority, funding model, interoperability agreements and independent oversight are governance matters requiring formal approval and documentation.