URI scheme¶

This page records which IRIs Indicium uses, which of them resolve today, and what the pending registration will add. Every status below was measured on 2026-10-30.

Namespaces¶

Prefix	Namespace	What it names	Resolves today
`asb:`	`https://w3id.org/asb#`	`asb:Claim` and eight slot IRIs: the SuperPattern slots `asb:context`, `asb:subject`, `asb:qualifier`, `asb:relation`, `asb:object`, and `asb:domainQualifier`, `asb:sourceTaskKind`, `asb:workflowCoupling`	Yes
`asbval:`	`https://w3id.org/asb/validation#`	Validation assertion terms used by ASB beside `asb:`. Not a prefix of this schema	Yes
`indicium:`	`https://w3id.org/indicium/`	The LinkML schema `id`, the `indicium` prefix of the JSON-LD context, and every class and slot without its own `class_uri` or `slot_uri`: claim metadata (`claim_status`, `claim_type`, `source_excerpt`), the evidence and source slots (`eco_code`, `quote_exact`, `for_claim`, `of_source`, ...), `ClaimLink`, `CitationLink` and `IndiciumDocument`. The SHACL shapes check 75 property paths under this namespace, and the OWL artefact names every class and slot under it	No (404)

Code never needs to spell these strings. The bases are exported:

from indicium import ASB_BASE, INDICIUM_BASE, asb_term

ASB_BASE           # 'https://w3id.org/asb#'
INDICIUM_BASE      # 'https://w3id.org/indicium/'
asb_term("Claim")  # 'https://w3id.org/asb#Claim'

`https://w3id.org/asb#` and `https://w3id.org/asb/validation#`¶

Registered on w3id.org on 29 October 2026 (perma-id/w3id.org#7017). The redirects lead to documents hosted by the lab, which negotiate the representation:

Request	Redirect chain	Final response
`https://w3id.org/asb`, `Accept: text/turtle`	301 to `/asb/`, 303 to `https://holobiomicslab.eu/ns/asb`, 303 to `asb.ttl`	200 `text/turtle`
`https://w3id.org/asb`, `Accept: application/ld+json`	same, ending at `asb.jsonld`	200 `application/ld+json`
`https://w3id.org/asb`, `Accept: text/html`	same, ending at `asb.html`	200 `text/html`
`https://w3id.org/asb/validation`, `Accept: text/turtle`	303 to `https://holobiomicslab.eu/ns/asbval`, 303 to `asbval.ttl`	200 `text/turtle`
`https://w3id.org/asb/validation`, `Accept: text/html`	same, ending at `asbval.html`	200 `text/html`

The fragment of a hash IRI never reaches the server: https://w3id.org/asb#Claim is looked up in the document returned for https://w3id.org/asb. Cite the w3id IRIs, not the holobiomicslab.eu addresses behind them; the redirect target can change, the identifier does not.

`https://w3id.org/indicium/`¶

Not registered. https://w3id.org/indicium/ and every IRI under it return 404. The request files are ready in the repository, under docs/release/w3id-indicium/, and wait on two prerequisites: the repository must be public and GitHub Pages must be enabled. RELEASING.md lists the order.

The request files propose the rules below. They take effect only when the registration is merged, and they can change until then:

IRI	`Accept`	Target
`https://w3id.org/indicium/` and single-segment terms, for example `.../IndiciumDocument`	`text/turtle`	`docs/schema-assets/indicium.owl.ttl` on the `main` branch, via `raw.githubusercontent.com`
same	`application/ld+json`	`src/indicium/schema/context.jsonld` on `main`, via `raw.githubusercontent.com`
same	anything else	the documentation site, `https://holobiomicslab.github.io/indicium/`
`.../context.jsonld`	any	`src/indicium/schema/context.jsonld` on `main`, via `raw.githubusercontent.com`
`.../indicium.owl.ttl`, `.../indicium.shapes.ttl`, `.../indicium.schema.json`	any	the file in `docs/schema-assets/` on `main`, via `raw.githubusercontent.com`
`.../<X.Y.Z>/<one of those files>`	any	the file at the tag `v<X.Y.Z>`
`.../claim/<uuid>` and other multi-segment paths	any	404 (no service resolves instances)

Two names for one class in the generated artefacts¶

The SHACL shapes and the pydantic model use the class_uri and slot_uri of the LinkML source. They bind Claim and eight of its slots to asb: IRIs; Evidence, Source, Figure, Script, SoftwareEntity and DataAsset to SEPIO, FaBiO, DoCO and DCAT classes; the two selectors to Web Annotation (oa:) and SSSOMMapping to sssom:Mapping; a few slots to Dublin Core, PROV and SEPIO properties; and every other class and slot to its indicium: IRI. Of the 87 property paths in the shapes, 75 are under indicium: and 8 under asb:.

The OWL artefact, indicium.owl.ttl, is generated with the LinkML default that names each class and slot by its schema-native IRI under indicium:, including those bound elsewhere: it declares 60 IRIs typed owl:Class (classes, enums and enum values), 58 owl:DatatypeProperty and 34 owl:ObjectProperty under https://w3id.org/indicium/. The ontology document itself is https://w3id.org/indicium. Each class bound elsewhere carries skos:exactMatch to that IRI (indicium:Claim to asb:Claim, indicium:Evidence to SEPIO_0000002, ...); the slots carry no such mapping. Validate data against the SHACL shapes. Most properties they check are indicium: IRIs, so the pending /indicium registration matters for claim and evidence data, not only for document-level terms.

Entity identifiers¶

Producers mint their own identifiers; Indicium does not allocate them. Producers may use identity IRIs such as:

https://w3id.org/indicium/claim/<uuid>
https://w3id.org/indicium/evidence/<uuid>
https://w3id.org/indicium/source/<uuid>
https://w3id.org/indicium/software-entity/<uuid>

<uuid> is a UUIDv4 from the producing pipeline.
The producing system allocates and stores its instances. Indicium provides no central store and no resolver for individual UUIDs. These IRIs are names, not addresses: no service dereferences them, and the proposed /indicium rules leave multi-segment paths unserved.
Some consumers cite <identity>@sha256:<hex> as an immutable citation identifier. The hash is meaningful only with the producer's documented canonicalization and the preserved payload; sorting JSON keys is not by itself a standard RDF canonicalization. This package does not compute or verify these hashes.

The KGmemory adapter separately emits urn:indicium:claim:<id>. URNs are identifiers, not HTTP addresses. Its http://kgmemory.org/ns# base is a legacy external dependency; do not infer current ownership or availability from its presence in an export.

JSON-LD context¶

The context is docs/context.jsonld in the repository, identical to src/indicium/schema/context.jsonld, which ships in the wheel. It is generated from the class_uri, slot_uri and enum meanings of the LinkML source (make context), so its term IRIs are the ones the SHACL shapes check. No public URL serves it today. Until one does, load it from the installed package:

from importlib.resources import files

context = (files("indicium") / "schema" / "context.jsonld").read_text()

After the release it will be served by the documentation site at https://holobiomicslab.github.io/indicium/context.jsonld and, once registered, at https://w3id.org/indicium/context.jsonld.

Namespace	Owner	Resolves today
`https://w3id.org/holobiomicslab/asb-skill/...`	asb-skill-collections	Yes. Registry, contributors, leaderboard and collection paths have their own rules; every other path redirects (302) to the repository
`https://w3id.org/holobiomicslab/asb-tool/...`	asb-skill-collections	Redirects (302) to the same repository; there is no dedicated rule yet

An ASB-Tool IRI may appear as the value of SoftwareEntity.identifier, so one tool can be both a node in an Indicium graph and a citable release record.

Stability¶

A term IRI never changes after a tagged release. Published data embeds it.
Adding a class, a slot or an enum value is a minor version.
Changing an IRI, removing a slot, or tightening a cardinality is a major version. This is why the move of the asb: base to https://w3id.org/asb# was 2.0.0.