# Scopes (/docs/reference/scopes)

The items each scope produces, and what their diagnostics point at.



The `scope` of a rule, or of one of its checks, decides the items the condition runs against, the [fields](/docs/reference/fields) it can read and where each diagnostic points.

| `scope`    | Evaluated against                                       | Diagnostic points at | Timeline position  |
| :--------- | :------------------------------------------------------ | :------------------- | :----------------- |
| `sequence` | the sequence, once                                      | the sequence         | none               |
| `track`    | every video track, then every audio track               | the track            | none               |
| `clip`     | every clip of every track, video tracks first           | the clip             | the clip's start   |
| `effect`   | every user-applied effect of every clip, in chain order | the effect's clip    | the clip's start   |
| `marker`   | every sequence marker                                   | the marker           | the marker's start |

A check's `location` replaces the timeline position: see [Checks](/docs/guides/checks#where-the-diagnostic-points).

## Fields by scope [#fields-by-scope]

| `scope`    | Field prefixes                                        |
| :--------- | :---------------------------------------------------- |
| `sequence` | `sequence.`, `options.`                               |
| `track`    | `track.`, `sequence.`, `options.`                     |
| `clip`     | `clip.`, `track.`, `sequence.`, `options.`            |
| `effect`   | `effect.`, `clip.`, `track.`, `sequence.`, `options.` |
| `marker`   | `marker.`, `sequence.`, `options.`                    |

In the `clip` and `effect` scopes, `track.*` is the clip's own track.

## Computed scopes [#computed-scopes]

Some [built-in rules](/docs/rules) name a computed scope instead, such as `video-gaps` or `scale-outliers`. PPROLint computes their items: a gap between clips, a clip compared with the other clips of its track or sequence. A custom rule may use them too. [Computed scopes](/docs/reference/computed-scopes) lists each with its fields, the options it reads and the built-in rules that use it.