Datasets:

maxwellinked
/

time-lapse-artifacts

Physical_References/endpoint_references.csv is a derived relational sidecar. It is not a third canonical media index and it does not modify the 29-field video metadata contract. Join it to metadata.csv on record_id after pinning both artifacts to the same repository revision.

Each row represents one active, owner-confirmed relationship between a canonical Standard video record and a photographed state or side of a physical work. Version 0.1 has one row per linked record_id.

Identity fields

Field	Type	Meaning
`reference_id`	string	Stable derived identity: `tlar-` plus 16 lowercase hex characters.
`record_id`	string	Persistent canonical video identity.
`canonical_file_name`	string	Repository-relative video path at `source_hub_revision`.
`source_hub_revision`	40-char hex	Exact Hub revision used for the join.

Record context

record_date, record_time, dimensions, tool, medium, and support are copied from the pinned canonical metadata for review convenience. They must not be independently edited in the sidecar. Blank time remains unknown.

Reference fields

Field	Type	Meaning
`reference_image_filename`	string	Source photograph filename; descriptive, not identity.
`reference_image_number`	string	Retained source number token.
`reference_image_role`	enum-like string	Literal role from the reviewed owner ledger.
`paired_image_filename`	string or blank	Associated back/opposite-side evidence when present.
`reference_image_sha256`	hex or blank	SHA-256 only when found in a current source ledger.
`paired_image_sha256`	hex or blank	SHA-256 only when found in a current source ledger.
`hash_state`	string	Mechanical summary of which source-ledger hashes are present.
`source_photo_collection`	semicolon list	Local source-ledger origin, not a public URL.

hash_state must agree with the two hash columns exactly:

Front hash	Paired hash	Required state
present	present	`front_and_paired_hashes_verified`
present	blank	`front=verified_from_local_source_ledger;paired=not_available_in_current_source_ledgers`
blank	blank, paired filename present	`front=not_available_in_current_source_ledgers;paired=not_available_in_current_source_ledgers`
blank	blank, paired filename blank	`not_available_in_current_source_ledgers`

A paired hash requires a paired filename. These states report ledger availability only; they do not visually authenticate an unbundled photograph.

Relationship fields

Field	Meaning
`relationship_type`	Conservative relationship category derived from explicit evidence.
`surface_scope`	Front, side A/B, unresolved side, or later front state.
`temporal_scope`	Whether endpoint, longitudinal, or temporally unspecified.
`endpoint_claim_state`	Explicitly states whether an endpoint claim is supported.
`pairing_state`	State of the associated paired/back image.
`owner_confirmation_state`	Owner-confirmed record link in every current row.
`evidence_state`	Lossless semicolon list copied from the active mapping ledger.
`owner_evidence`	Human-readable creator confirmation.
`paired_image_evidence`	Human-readable reverse/back qualification.

Observed and currently validated relationship_type values:

endpoint_photograph
longitudinal_continuation
owner_confirmed_record_reference
two_sided_work_reference

longitudinal_continuation must never be used as exact endpoint supervision. Two-sided relationships must not be collapsed into one assumed visual surface.

Media availability

reference_media_availability is local_evidence_only_not_bundled_v0.1. Photographs are not downloadable in this release. The two proposed-path columns are intentionally blank and must not be interpreted as Hub paths.

Missing values

Blank means unknown, not documented, unavailable in current ledgers, or not applicable. It never means zero or false. Do not fill missing hashes, timestamps, side roles, or temporal states by visual guess.

Validation

Physical_References/MANIFEST.json binds the sidecar bytes and the exact historical metadata.csv used for the original join. Validate all structural, join, hash-state, count, and manifest invariants with:

python tools/validate_physical_references.py \
  --references Physical_References/endpoint_references.csv \
  --metadata /path/to/pinned/metadata.csv \
  --manifest Physical_References/MANIFEST.json

This is consistency validation, not visual re-review. It does not infer a pair, endpoint, date, material, or physical state from filenames or images.

ML boundary

machine_use_scope and caution describe supported selection/alignment uses. They are not task labels, training splits, performance claims, or permission to treat encoded video time as physical drawing time.