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Redirects and Content Negotiation Policy

Status: Deployed and verified live (perma-id/w3id.org#6277, #6292); re-verified 2026-07-08 — see Verification Result below
Date: 2026-07-01 (re-verified 2026-07-08)
Scope: Current XwkOnt core ontology namespace and first ontology milestone preparation

Purpose

This document specifies the minimal public redirect and content-negotiation behavior needed before XwkOnt advertises dereferenceable public IRIs for the current core ontology namespace.

The behavior is intentionally small and practical. It does not activate immutable versioned ontology document IRIs.

Decision Summary

Question Decision
Are public IRI redirects ready to specify? Yes. Expected behavior is specified here, but deployment must still be configured and verified.
Is content negotiation ready to specify? Yes. Minimal HTML/Turtle behavior is specified here, but deployment must still be configured and verified.
Should dereferenceability be advertised now? No. It may be advertised only after deployed behavior is tested.
Are immutable versioned ontology document IRIs active? No. They remain deferred.

Current Core Namespace

The current core term namespace is:

https://w3id.org/xwkont/core#

Because it is a hash namespace, clients retrieve the namespace document at:

https://w3id.org/xwkont/core

Expected Retrieval Behavior

Requests to the current namespace document should support these outcomes:

Request Expected response
GET https://w3id.org/xwkont/core with Accept: text/turtle Redirect or serve Turtle for data/ontology/core.ttl.
GET https://w3id.org/xwkont/core with Accept: application/x-turtle Redirect or serve Turtle for data/ontology/core.ttl.
GET https://w3id.org/xwkont/core with Accept: text/html Redirect or serve human-readable documentation for docs/ontology/core-ontology.md or the repository-rendered equivalent.
GET https://w3id.org/xwkont/core with no explicit useful Accept header Prefer human-readable documentation.

Redirects may point to repository-hosted raw Turtle and repository-rendered documentation while the project remains repository-first.

Minimal w3id Configuration Expectation

The persistent base should be configured so that:

  • https://w3id.org/xwkont/core resolves to current core ontology documentation or Turtle based on content negotiation.
  • Fragment IRIs such as https://w3id.org/xwkont/core#Entity remain term IRIs and rely on retrieval of the fragmentless namespace document.
  • https://w3id.org/xwkont/ resolves to the project entry point or repository landing page.

Implementation should use the external request in docs/publication/w3id-redirect-request.md unless maintainers choose another w3id-supported mechanism. This repository has no active w3id deployment configuration of its own, so deployment ownership remains external to this repository.

Non-Goals

This policy does not:

  • create source-ontology correspondences;
  • treat example data as authoritative;
  • adopt OWL as the default modeling layer;
  • define persistent IRIs for source ontology terms;
  • activate immutable versioned ontology document IRIs;
  • require a full web application or documentation site.

Verification Commands

After redirects are deployed, maintainers should verify behavior with commands equivalent to:

curl -I -L -H 'Accept: text/turtle' https://w3id.org/xwkont/core
curl -I -L -H 'Accept: text/html' https://w3id.org/xwkont/core
curl -L -H 'Accept: text/turtle' https://w3id.org/xwkont/core | head
curl -L -H 'Accept: text/html' https://w3id.org/xwkont/core | head

Expected results:

  • Turtle requests ultimately return Turtle content for the current data/ontology/core.ttl artifact.
  • HTML requests ultimately return human-readable core ontology documentation.
  • Redirect chains are stable enough to document in release notes.
  • No versioned ontology document IRI is claimed unless the release-versioning prerequisites are complete.

Verification Result

Superseded — this section described the pre-deployment state. An earlier attempt to check https://w3id.org/xwkont/ and https://w3id.org/xwkont/core on 2026-07-01 returned curl: (56) CONNECT tunnel failed, response 403 from that environment; a 2026-07-02 recheck found https://w3id.org/xwkont/ live but https://w3id.org/xwkont/core still 404 pending the content-negotiation rules described above. Both gaps have since closed: perma-id/w3id.org#6292 (merged 2026-07-03) added the /core content-negotiation rules, and docs/releases/core-ontology-release-notes.md's "Content-Negotiation Verification" section recorded the 2026-07-03 verified-live result. This document's own status line above simply hadn't been updated to match — fixed 2026-07-08.

Re-verified live, 2026-07-08 (this session, real curl against the deployed redirect, no changes needed):

  • curl -I -L -H 'Accept: text/turtle' https://w3id.org/xwkont/core → 302 → https://raw.githubusercontent.com/xwkont/xwkont/main/data/ontology/core.ttl → final 200.
  • curl -I -L -H 'Accept: text/html' https://w3id.org/xwkont/core → 302 → https://github.com/xwkont/xwkont/blob/main/docs/ontology/core-ontology.md → final 200.
  • curl -I -L https://w3id.org/xwkont/core#Entity → same 302/200 as the fragmentless namespace document, confirming fragment IRIs resolve correctly.
  • curl -I -L https://w3id.org/xwkont/ → 302 → https://github.com/xwkont → final 200.
  • Served Turtle body's class count (grep -c 'a owl:Class') matches data/ontology/core.ttl's local count (30) exactly — the deployed content reflects the current 0.3.0-era core.ttl, not a stale cached copy.
  • https://w3id.org/xwkont/ontology/core/0.1.0 (the immutable versioned document path) still returns 404, consistent with "Blockers Before Advertising Dereferenceability" below — versioned IRIs remain correctly un-activated.

HTML Pages retarget submitted 2026-07-10 as perma-id/w3id.org#6343 (pending merge). After merge, expected HTML targets become:

  • https://w3id.org/xwkont/ → https://xwkont.github.io/xwkont/
  • https://w3id.org/xwkont/core (HTML / default) → https://xwkont.github.io/xwkont/ontology/core-ontology/
  • Turtle negotiation unchanged.

Re-run the verification commands above after #6343 merges and record the new Location headers here.

Full dereferenceability of the current (non-versioned) namespace is live and verified; only immutable versioned document IRIs remain deferred.

The implementation blockers are tracked in docs/publication/w3id-redirect-request.md: the canonical repository target must be confirmed by a maintainer, the redirect configuration must be submitted to external w3id infrastructure, and deployed behavior must be verified after deployment.

Blockers Before Advertising Dereferenceability

XwkOnt must not advertise public dereferenceability until:

  1. w3id.org redirect configuration is merged or otherwise deployed.
  2. Turtle retrieval is verified.
  3. HTML retrieval is verified.
  4. Verification results are recorded in release notes.
  5. The README and publication guide are updated from target-namespace language to verified-dereferenceability language.

All five are satisfied for the current (non-versioned) namespace as of the 2026-07-08 re-verification above. This does not extend to immutable versioned ontology document IRIs, which remain a separate, still-deferred decision (see TODO.md's "Publication & Release" section).