Glossary

The words this site uses about its own data, and what each of them does and does not claim. Terms are linked from their first appearance on every page, so you can arrive here from wherever the word confused you.

Several of these exist because a reader guessed wrong, and the guess was always in the same direction: that a figure means more than it does. So the definitions say what a term excludes as well as what it covers. Where a term has a stricter technical reading, the Precisely line carries it.

small

An hour holding under a quarter of the median hour's bytes for its corpus.

Precisely. A fact about volume, never a verdict about capture. Several small hours are attested complete for all sixty minutes and simply had little to record: 2026-08-19T04 sits at about 5% of median and is whole. A quiet market and a capture problem look the same from the outside, which is why the marker names its reason where one is known and says so plainly where none is.

witness

An independent machine recording the same live feed. An hour's witness letters name the machines that supplied rows to the merged hour, and contribution is counted by rows supplied rather than by being online. More witnesses mean more cross-checking, not more data.

Precisely. Rendered from contributing_domains, or from rows_by_domain > 0 where that field is absent. Never from the w= string, which lists the machines expected to be capturing and so overstates the count on any hour where one was present and empty.

boundary drops

Duplicate events discarded at the seam between two adjacent hours during the merge.

Precisely. A small count is ordinary bookkeeping. A spike is investigated and annotated on the hour rather than smoothed away, because the seam is exactly where a merge defect would show first.

found-vs-traded

Of the markets that traded in an hour by the exchange's own record, the share our capture also saw.

Precisely. The denominator is theirs, not ours. A ratio computed against our own market list would measure how consistent we are with ourselves, which is not a question anybody is asking.

dedup

Identical events reported by several witnesses collapsed to one row.

Precisely. The gap between the joined count and the merged count is deduplication, not data loss. Redundant capture is the point of running several machines, so a large delta on a busy hour is the design working.

audit pending

We have not looked yet.

Precisely. Not a synonym for complete and never a verdict. A section whose instrument has not run says this and says nothing else; the alternative is a page that reads as an all-clear nobody measured.

verdict

An hour's completeness on minutes: complete means all sixty are present, partial means some are not.

Precisely. A partial hour states which minutes are missing, with the first and last timestamps actually present and a mechanism where one is known. Neither word says anything about whether the rows in the hour are correct.

supersession

An hour rebuilt to a better state, for instance when a witness that had been missing is healed in.

Precisely. The archive improves in place and the history is listed on the hour's own report, so a reader who downloaded the earlier version can see that it changed and why.

manifest

An hour's machine-readable record of what it contains and the digest of each part.

Precisely. Every number on an hour's audit page is read from its manifest, its witness-statistics sidecar or the corpus attestation. Nothing is computed from the served bytes when the page loads.

sidecar

A companion file published beside the data, such as witness statistics or a checksum ledger.

Precisely. Sidecars are derived from the corpus and must be measured. The incident register is authored rather than derived, which is why it is served from the worker instead of the bucket.

attestation

The published per-hour completeness record the site renders its verdicts from.

Precisely. Distinct from the comparison audit, which scores book sets across corpora. Two instruments, two scopes: the attestation covers our own union, the comparison census covers the mirrored eras.

era

A dated change in how hours are produced, recorded in the gap ledger.

Precisely. Comparisons across an era boundary carry a line break rather than a smoothed join, because a curve drawn through a change of method invites a reading of a trend that is really a change of instrument.

precision

The timestamp resolution an hour's files carry, in microseconds or nanoseconds.

Precisely. Stated because it changed on a known date. The exchange's own timestamp is milliseconds throughout and is a different field from the receive timestamp; neither is interchangeable with the other.

snapshot grade

Hours that record book states without carrying every event between them.

Precisely. A statement about method, not about worth. The word snapshot here names the grade and not the book_snapshot event type, which is a different thing with a confusingly similar name.

A word that is not here

If this site uses a term about its own data that this page does not define, that is a defect rather than an oversight on your part. The build refuses a term that is linked and undefined, but it cannot catch a word nobody thought to link. Tell us and it gets an entry.