# Identifier limits

An identifier is a string of characters used to identify "named" [objects in Pinecone](/guides/core-concepts-key-terms). The following Pinecone objects use strings as identifiers:

| Object                                                       | Field       | Max # characters | Allowed characters                                                                                                   |
| ------------------------------------------------------------ | ----------- | ---------------- | -------------------------------------------------------------------------------------------------------------------- |
| [Organization](/guides/core-concepts-key-terms#organization) | `name`      | 512              | - UTF-8 except `\0`  - Cannot be empty                                                                               |
| [Project](/guides/core-concepts-key-terms#project)           | `name`      | 512              | - UTF-8 except `\0`  - Cannot be empty                                                                               |
| [Index](/guides/core-concepts-key-terms#index)               | `name`      | 45               | - `a-z`, `0-9`, and `-`  - Must be lowercase  - Cannot start or end with `-`  - Cannot be empty                      |
| [Namespace](/guides/core-concepts-key-terms#namespace)       | `namespace` | 512              | - ASCII except `\0`  - For the default namespace, use `""` (or `"__default__"`, in API versions `2025-04` and later) |
| [Record](/guides/core-concepts-key-terms#record)             | `id`        | 512              | - ASCII except `\0`  - Cannot be empty                                                                               |

## Related pages

- [Pinecone Database limits overview](./apis-database-limits.md)
- [Rate limits](./apis-database-limits-rate-limits.md)
- [Object limits](./apis-database-limits-object-limits.md)
- [Operation limits](./apis-database-limits-operation-limits.md)
- [Known limitations](./apis-known-limitations.md)

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