Draft consultation shape

TLA-Sub — Plant substitution / equivalency

Draft orbit: portable pack for documenting plant substitutions and equivalency claims beside the spine.

Schema id: la.archive.substitution.v1 · Spine: TLA-185

Purpose

Define a portable substitution pack so phase handovers can record which plant was specified, what replaced it, on what equivalency basis, and which TLA-185 taxon fields the claim sits on.

TLA-185 remains the botanical authority. This orbit profiles substitution lineage and reviewer-readable equivalency notes.

Out of scope

Not this orbit	Where it lives
Archive Seal issue / crypto	Commercial Archive attestation
Procurement approval workflow	Project / ERP systems
A second plant field registry	Spine — TLA-185
World flora dump	Forbidden expansion path

Enumerations (draft — freeze later)

Field	Allowed values (draft)
`phase`	`design \| tender \| construction \| maintenance \| as_built \| other`
`equivalency.basis`	`botanical \| functional \| aesthetic \| cost \| availability \| other`
`equivalency.confidence`	`documented \| partial \| asserted \| unknown`

Normative intent (when elevated from Draft)

When elevated from draft: substitutions that affect botanical or sustainability claims should be linkable from this pack via tla185_refs.
Equivalency basis and confidence must be expressible. Silence is worse than asserted without documentation.
Commercial products may embed richer approval workflows; the open pack is the portable audit subset.

Foundation vs Archive

Foundation	Archive
Publishes the open substitution shape for teaching, RFQ language, and phase handover.	May implement richer substitution tooling and paid attestation products.
Does not issue Archive Seal.	Archive Seal remains a separate commercial attestation.

Golden example (illustrative)

Minimal worked example for consultation. Not a production product API. Download JSON · Required-keys schema (Draft). Repo smoke: npm run validate:orbits.

{
  "schema_id": "la.archive.substitution.v1",
  "schema_version": 1,
  "pack_id": "sub-ex-001",
  "created_at": "2026-07-26T00:00:00.000Z",
  "substitution": {
    "original_ref": "spec-tree-001",
    "substitute_ref": "installed-tree-014",
    "reason_note": "Stock unavailable at tender; functional equivalent approved"
  },
  "equivalency": {
    "basis": "functional",
    "confidence": "documented",
    "reviewer": null,
    "method_note": "Horticulturist sign-off recorded in project minutes"
  },
  "phase": "construction",
  "tla185_refs": {
    "record_id": null,
    "field_paths": ["planting.taxon", "planting.quantity"]
  }
}