---
generated: '2026-08-19'
method: probed
source: >-
  Live probes on 2026-08-19, including deliberate negative probes against real path shapes rather
  than nonsense paths, so that soft-404 behaviour would be detected if present.
x-operator: institution

summary: >-
  Both institution-operated surfaces return honest HTTP status codes. Neither returns a 200 with an
  error body, and neither returns a machine-readable error object — errors are plain HTTP semantics
  with an HTML or minimal body. There is no problem+json, no error code vocabulary and no
  documented retry guidance, which is the main ergonomics gap on an otherwise clean surface.

surfaces:

- surface: IIIF Presentation API
  base: https://www.digitalcollections.manchester.ac.uk
  x-operator: institution
  media_type_on_error: text/html
  machine_readable_errors: false
  observed:
  - probe: https://www.digitalcollections.manchester.ac.uk/iiif/MS-LATIN-00006
    status: 200
    note: Known document; valid sc:Manifest.
  - probe: https://www.digitalcollections.manchester.ac.uk/iiif/NOT-A-REAL-ID-12345
    status: 404
    bytes: 14680
    note: >-
      Unknown document on a real path shape. Genuine 404 with the site's HTML error page — no soft-200.
  - probe: https://www.digitalcollections.manchester.ac.uk/iiif/collections/latin
    status: 404
    note: Wrong path segment (plural). Correctly 404s; the working form is /iiif/collection/{id}.
  - probe: https://www.digitalcollections.manchester.ac.uk/search/JSON?keyword=manchester
    status: 400
    note: >-
      Rejects a malformed request with 400 rather than silently returning an empty result set.

- surface: IIIF Image API
  base: https://image.digitalcollections.manchester.ac.uk
  x-operator: institution
  media_type_on_error: text/html
  machine_readable_errors: false
  observed:
  - probe: https://image.digitalcollections.manchester.ac.uk/iiif/MS-LATIN-00006-000-00001.jp2/info.json
    status: 200
    note: Known image; valid info document.
  - probe: https://image.digitalcollections.manchester.ac.uk/iiif/NOT-REAL.jp2/info.json
    status: 404
    bytes: 196
    note: Unknown identifier on a real path shape. Genuine 404, minimal body.
  - probe: https://image.digitalcollections.manchester.ac.uk/
    status: 403
    bytes: 199
    note: >-
      Bare root is forbidden by design — the server exposes no directory listing. A 403 here is a
      finding about configuration, not a dead host; every real IIIF path under it returns 200.

gaps:
- No RFC 9457 / problem+json error representation on any institution-operated surface.
- No documented error catalogue, error codes or retry guidance.
- No rate-limit headers observed on any successful response.