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

# Segments Reference

> Technical reference for Confidence Segments.

This section provides technical specifications and reference information for Confidence Segments.

<Tip>
  For conceptual explanations of segments, see [Segments](./concepts#segments) in the Flag Concepts page.
</Tip>

## Segment States

Segments have three lifecycle states:

| State           | Description                                             |
| :-------------- | :------------------------------------------------------ |
| **UNALLOCATED** | Initial state after creation                            |
| **ALLOCATED**   | Active and ready to use in flag rules                   |
| **ARCHIVED**    | No longer in use but preserved for historical reference |

You must allocate a segment before using it in a flag rule.

## Targeting Criteria

### Expression Operators

Supported expression operators:

| Operator | Description                        |
| :------- | :--------------------------------- |
| `ref`    | Reference a named criterion        |
| `not`    | Logical NOT of a nested expression |
| `and`    | Logical AND between expressions    |
| `or`     | Logical OR between expressions     |

### Attribute Value Types

Available value types:

| Type      | Description               | Example                  |
| :-------- | :------------------------ | :----------------------- |
| Boolean   | Boolean value             | `true`, `false`          |
| Number    | Integer or floating point | `42`, `3.14`             |
| String    | String value              | `"HELLO"`                |
| Timestamp | ISO 8601 timestamp        | `"2023-01-01T00:23:54Z"` |
| Version   | Semantic version          | `"2.1.3"`                |

### Match Operators

* **Equality (`eqRule`)**: Match exact value
* **Set (`setRule`)**: Match any value from a set
* **Range (`rangeRule`)**: Match values within a range (supports inclusive/exclusive bounds and open-ended ranges)

## Coordination

### Common Coordination Patterns

1. **Mutual exclusion**: All experiments in a feature area exclude each other using the same tag
   Use `exclusivityTags: ["homepage"]` and `exclusiveTo: ["homepage"]`

2. **Hierarchical coordination**: Specific experiments exclude from broader categories
   * Specific: `exclusivityTags: ["ranking-v2"]` and `exclusiveTo: ["ranking-v2", "all-experiments"]`
   * Broad: `exclusivityTags: ["all-experiments"]` and `exclusiveTo: ["all-experiments"]`

3. **Cross-feature coordination**: Related features that shouldn't run simultaneously
   * Search: `exclusivityTags: ["search"]` and `exclusiveTo: ["search", "ui-changes"]`
   * UI: `exclusivityTags: ["ui-changes"]` and `exclusiveTo: ["search", "ui-changes"]`

### Best Practices

* Use descriptive tag names that clearly indicate the feature or experiment type
* Plan coordination strategy before creating segments
* Monitor allocation space within each coordination group
* Archive completed experiments to free up space
* Document which tags represent which feature areas