accepted 2026-08-23

Place the PDTF schema beneath SPDTF as a third-party input

Update 2026-09-03 — ADR-0074’s route amendment moves this reader hierarchy from /spdtf/inputs/pdtf-schema/** to /development/inputs/pdtf-schema/**. The source attribution, third-party status, preservation rules and separate /pdtf/** identifier namespace are unchanged.

Update 2026-08-23 — global-navigation correction: the site has six destinations in this order: Programme, Governance, Semantic modelling, SPDTF Development, Working groups and Resources. This changes the destination count, order and navigation label only. Semantic modelling is the canonical peer family at /semantic-modelling/**; it does not appear beneath SPDTF Development, and /spdtf/ontologies/** is retired without a redirect, rewrite alias or duplicate page. The PDTF schema remains a source-specific third-party input beneath /spdtf/inputs/pdtf-schema/**, and stable /pdtf/** RDF identifiers remain unchanged.

Context and Problem Statement

ADR-0076 gave PDTF schema documentation a separate top-level home. That placement makes the source look like a peer programme destination and can imply that its material was authored, adopted or governed through SPDTF. It was not. The PDTF schema is an existing third-party technical input used for evidence, compatibility and migration; SPDTF is the collaborative scheme draft that evaluates inputs through its own working-group process.

The separate schema-derived ontology remains an OPDA-produced technical derivation of that source. It is non-normative evidence, not third-party-authored, not SPDTF, and not evidence of working-group consensus. Property Pack remains an SPDTF candidate component, not an external input.

The operator has again authorised a clean route break: former reader routes may disappear, without redirects, once their content, fragments, assets and feedback identities have been verified at their replacement routes. The stable /pdtf/** RDF identifier namespace is outside this editorial change.

Considered Options

Keep the PDTF schema as a peer global destination. Rejected: that positioning implies a programme relationship and authority that the source does not have.
Keep its current root and add a cross-link from SPDTF. Rejected: a cross-link does not express the input relationship in the information architecture.
Put all PDTF material under a generic resources library. Rejected: readers need to see how this specific input informs SPDTF, while still keeping its authority separate.

Decision Outcome

The site has six global destinations, in this order: Programme, Governance, Semantic modelling, SPDTF Development, Working groups and Resources. The PDTF schema remains nested inside SPDTF Development as a source-specific, third-party input:

Semantic modelling owns the separate /semantic-modelling/** reader hierarchy. SPDTF Development has no Semantic modelling child branch, and /spdtf/ontologies/** is not emitted, redirected, rewritten, aliased or duplicated.

/spdtf
└── /inputs
    └── /pdtf-schema
        ├── /schema-and-supporting-material/**
        └── /schema-derived-ontology/**

/spdtf/inputs is a substantive input-policy landing, not a redirect or empty folder. It explains that inclusion means relevance to SPDTF work, not adoption, endorsement, authorship, control or semantic authority. It distinguishes three separate surfaces:

Resources records preserve raw, attributed source material.
Working-group evidence intake records participant submissions and access controls.
SPDTF inputs curate sources that are relevant to modelling, compatibility or review and record their source-specific disposition.

The PDTF schema landing must state: it is a third-party technical input retained for evidence, compatibility, migration and implementation; it was not produced through the SPDTF working-group process, is not an OPDA-endorsed scheme and does not determine SPDTF meaning. The schema-derived ontology landing must state its distinct draft, derived status.

/pdtf-schema/** is retired with no redirect, rewrite alias or duplicate canonical page. /spdtf/third-party-inputs/** is not a public route. /pdtf/** HTML and Turtle representations remain exact stable identifiers, including the distinct LeaseTerm and leaseTerm resources.

Route and information-preservation contract

Before moving any page, freeze schema-v8 as the immediate source manifest. Schema-v9 must carry a dedicated, source-pinned PDTF-schema-input receipt rather than rewriting older PDTF or schema-to-scheme receipts as though their intermediate destinations never existed. The receipt must prove all of the following:

every /pdtf-schema/** reader route and physical output maps once to /spdtf/inputs/pdtf-schema/**, preserving the exact suffix and flat *.html filenames;
no old reader route is emitted and no redirect is created;
every /pdtf/** route and file remains exact and is never classified as a move;
information blocks, authored anchors and generated-family inventories are retained or carry an explicit, hash-bound replacement receipt;
renamed navigation-shell fragments have a separate one-to-one fragment receipt; and
every Artalk key composes through the intermediate PDTF-schema route before the generic SPDTF route resolver, so existing discussion threads are not reminted.

The navigation owner of the new subtree is the SPDTF Development destination, while its content-owner/status metadata remains third-party PDTF-schema input. A route prefix must not inherit working-group authority. Tool and artefact families keep their individual provenance and status.

Consequences

Good: the information architecture expresses the schema-to-scheme relationship without presenting the schema as a peer or predecessor scheme.
Good: readers can discover source inputs where SPDTF explains how they are used.
Bad: old /pdtf-schema/** links intentionally return not found and must be rediscovered through search or the SPDTF inputs landing.
Neutral: source containment is navigational only; it does not settle any modelling or standards decision.

Confirmation

This decision authorises local implementation and validation only. It does not authorise publication, deployment, source adoption or a working-group determination. It is complete only when the schema-v9 route receipt, full build, link/crawl, strict preservation and relevant navigation/authority checks pass on the final case-sensitive production build.

More Information

Amendments

2026-08-24 — Case-independent Lease Term representation routes. The exact LeaseTerm and leaseTerm identifiers remain distinguishable in the source model. Their generated HTML/Turtle documents now use lowercase, type-scoped paths and the former case-only paths are retired without redirects or aliases. This removes the release-filesystem dependency while preserving the source identifiers displayed in each representation.