> ## Documentation Index
> Fetch the complete documentation index at: https://vaquill.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Response Fields

> Which fields a section carries, which corpus each one belongs to, and how to tell 'not applicable' from 'we do not have it'

A section object is one shape across every corpus, so a result always carries the
same keys whatever you searched.
Most of them will be `null`, because most belong to a different corpus.

A Federal Register rule has a docket number and a comment-close date.
A US Code section has a source credit and a chapter.
A court rule has a rule set.
None of those apply to the others, and a null there means the field does not
apply, not that we are missing it.

This page tells the two apart.

## The rule

<Note>
  A `null` on a field this page marks as **not applicable** for your `corpusType`
  carries no information. A `null` on a field marked **expected** is a real gap,
  and worth telling us about.
</Note>

## Always present

These carry a value on every section in every corpus.

| Field | Meaning |
| - | - |
| `actId` | The stable identifier. Use it for every follow-up call. |
| `citation` | The full citation, including the edition year where the publisher prints one. |
| `citationShort` | The citation without the edition year. |
| `title` | The section's own heading. |
| `corpusType` | Which body of law this came from. |
| `state` | `federal`, or the two-letter jurisdiction. |
| `actStatus` | `in_force`, `repealed`, `superseded`, `reserved` and similar. |
| `goodLawStatus` | Our verdict on whether it is still good law. See [Status & Currency](/docs/api-guide/concepts/status-and-currency). |
| `externalUrl` | The publisher's own page for this section. |

## By corpus type

`o` = expected to carry a value. `-` = not applicable, ignore the null.

| Field | USC | CFR | STATE | FEDERAL\_REGISTER | EXECUTIVE\_ACTION |
| - | :-: | :-: | :-: | :-: | :-: |
| `titleNumber` / `titleName` | o | o | o | - | - |
| `chapter` / `chapterName` | o | - | o | - | - |
| `subchapter` / `subchapterName` | o | - | o | - | - |
| `part` / `partName` | - | o | - | - | - |
| `subpart` / `subpartName` | - | o | - | - | - |
| `sourceCredit` | o | - | - | - | - |
| `publicLawCites` | o | - | - | - | - |
| `currentThrough` | o | - | - | - | - |
| `amendmentYears` / `lastAmendedYear` | o | o | o | o (final rules) | o |
| `effectiveDate` | o | - | o | o (final rules) | o |
| `statutoryAuthority` | - | o | o | - | - |
| `frDocketIds` / `frRegulationIdNumbers` | - | - | - | o | - |
| `frEffectiveOn` / `frCommentsCloseOn` | - | - | - | o | - |
| `frVolume` / `frStartPage` | - | - | - | o | - |
| `president` / `signingDate` | - | - | - | - | o |
| `documentNumber` | - | - | - | o | o |

Two families sit outside this table because they belong to corpora it does not
have a column for.
`ruleSet` and `ruleSetCode` belong to `STATE_RULES` and `FEDERAL_RULES`.
`articleNumber` and `articleName` belong to `CONSTITUTION` and
`STATE_CONSTITUTION`.

## Version and supersession fields

These are populated where a publisher states the relation itself, and null
everywhere else.
Null here means the publisher drew no link we could read, not that the field is
unimplemented.

| Field | Meaning |
| - | - |
| `supersededBy` | `actId` of the document that replaced this one. |
| `supersedes` | `actId` of the earlier document this one replaced. |
| `priorEffectiveDates` | Earlier effective dates the publisher records for the same section. |
| `versionId` | The publisher's own identifier for THIS version of the document. |

Where each one actually carries a value:

* `supersededBy` and `supersedes` are populated on the corpora whose publishers
  print a supersession statement: state agency guidance bulletins, state court
  rules, and the `I&N Dec.` reporter under `AGENCY_ADJUDICATION`.
  A document can supersede several predecessors, so the value can be more than
  one `actId` joined by `; `.
  See [Status & Currency](/docs/api-guide/concepts/status-and-currency) for how to
  read the direction of the link before treating it as fatal.
* `versionId` is populated where a publisher versions a document separately from
  the document itself, which today means Colorado regulations, where it is the
  only version pointer that exists.

## Point-in-time text: `asOf`

`GET /us/statutes/section/{actId}/body` accepts `asOf=YYYY-MM-DD` and returns the section's text as
it stood on that date, billed as an ordinary body fetch.
The response carries an `asOf` block naming what you are holding: a published edition, a
reconstruction from observed change history, or neither.

Read `source` and `isBounded` before using the text.
`isBounded: true` means we observed no change affecting that date, which is not the same as there
having been none.

**Full contract, per-corpus behaviour and the billing rules are on
[Point-in-time law](/docs/api-guide/point-in-time).**

## Amendment fields on the Federal Register

`amendmentYears` on a **final rule** is the year that rule was published, which
is the year it amended the CFR.
A **proposed rule** carries no amendment years at all, because it amended
nothing.

That asymmetry is deliberate.
A proposed rule that was never finalized, or was withdrawn, must not look like
enacted law on the field a currency query trusts.

## Filtering by year

`yearFrom` and `yearTo` match a section on any of three years, in this order:

1. `lastAmendedYear`, the publisher's own credited amendment.
2. The year of the section's `effectiveDate`, for a section adopted once and
   never amended. Calling an adoption an amendment would be a wrong answer
   rather than a missing one, so those sections carry no `lastAmendedYear` and
   are reached this way instead. The year itself is an index field and is not
   returned on a result; read `effectiveDate` for the date it came from.
3. The document's own **publication or issue year**, for the corpora where that
   is what the document is dated by: Federal Register proposed rules, agency
   guidance, adjudications and the treaty record.

<Note>
  The third case is deliberately scoped to those corpora and is **not** a general
  fallback. On statutes and regulations the underlying year field records when we
  last ingested the text, not when the law changed, so matching it would answer a
  recent-year window with entire state codes.
</Note>

A section carrying none of the three is not reachable by a year filter and
returns zero results rather than an error.
That is why a proposed rule is reachable by its publication year while carrying
no `amendmentYears`: "when was this published" and "what did this amend" are
different questions, and only the second one is silent for a proposal.

## Related

* [Corpus Types](/docs/api-guide/concepts/corpus-types) for what each corpus contains.
* [Amendment History](/docs/api-guide/concepts/amendment-history) for where the years come from.
* [Status & Currency](/docs/api-guide/concepts/status-and-currency) for `actStatus` and `goodLawStatus`.


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