Summary
§4.1 gives a concept one clock: timestamp, "last meaningful change." For bundles whose concepts point at external resource URLs, that conflates two things a consumer needs to distinguish — when the content changed vs. when a producer last fetched or verified it — and the spec has no home at all for a third signal: whether the resource still resolves.
This is adjacent to #97 (elevate timestamp) and the maintenance-signals discussion in #158, but scoped to the producer-side fields those threads don't cover: retrieval/verification dates and source liveness.
Evidence (civic public records, where sources rot fast)
We maintain an OKF v0.1 bundle of local-government records for a large county in the US Northeast. Within the bundle's first year we hit, in production:
- Sources vanishing under live atoms: a town's public-hearing notices disappeared from its news feed before the year ended. The atom is fine; its
resource is gone. Nothing in the format records or reveals that.
- Verification as a distinct event: libraries post board minutes months late; a fact can be re-verified unchanged long after its content
timestamp. A consumer deciding whether to trust a figure needs "verified last week" vs. "verified last year," which timestamp cannot express without destroying its content-change meaning.
- Liveness is checkable but nontrivial: we run a sweep that GETs every
resource in the bundle (~160 URLs). Getting truthful answers required a browser user-agent, per-host politeness delays, and 429 backoff — civic-portal hosts throttle and UA-block. It's exactly the kind of shared problem a documented convention (plus a reference tool) would keep every producer from re-solving.
Proposal (all optional, all additive under §4.1 / §11)
retrieved_at — when the producer last fetched the resource.verified_at — when a human or pipeline last confirmed the concept still matches its source.- A
source_status convention — last-checked date + last observed HTTP state for the resource (e.g. {checked: 2026-07-02, state: ok | dead | blocked}).
Consumers that don't know the fields ignore them; nothing about §9's permissive-consumption contract changes. A v0.1 bundle stays conformant.
We have a working liveness checker (Python, no dependencies beyond the standard library + requests) built for this bundle and would be glad to contribute it as a reference implementation if there's interest.
Summary
§4.1 gives a concept one clock:
timestamp, "last meaningful change." For bundles whose concepts point at externalresourceURLs, that conflates two things a consumer needs to distinguish — when the content changed vs. when a producer last fetched or verified it — and the spec has no home at all for a third signal: whether theresourcestill resolves.This is adjacent to #97 (elevate
timestamp) and the maintenance-signals discussion in #158, but scoped to the producer-side fields those threads don't cover: retrieval/verification dates and source liveness.Evidence (civic public records, where sources rot fast)
We maintain an OKF v0.1 bundle of local-government records for a large county in the US Northeast. Within the bundle's first year we hit, in production:
resourceis gone. Nothing in the format records or reveals that.timestamp. A consumer deciding whether to trust a figure needs "verified last week" vs. "verified last year," whichtimestampcannot express without destroying its content-change meaning.resourcein the bundle (~160 URLs). Getting truthful answers required a browser user-agent, per-host politeness delays, and 429 backoff — civic-portal hosts throttle and UA-block. It's exactly the kind of shared problem a documented convention (plus a reference tool) would keep every producer from re-solving.Proposal (all optional, all additive under §4.1 / §11)
retrieved_at— when the producer last fetched theresource.verified_at— when a human or pipeline last confirmed the concept still matches its source.source_statusconvention — last-checked date + last observed HTTP state for theresource(e.g.{checked: 2026-07-02, state: ok | dead | blocked}).Consumers that don't know the fields ignore them; nothing about §9's permissive-consumption contract changes. A v0.1 bundle stays conformant.
We have a working liveness checker (Python, no dependencies beyond the standard library + requests) built for this bundle and would be glad to contribute it as a reference implementation if there's interest.