> For the complete documentation index, see [llms.txt](https://developer.collibra.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.collibra.com/api/guides/import-api/validation/operation-identifier-validation.md).

# Operation identifier validation

For each operation, the validation checks that the identifiers exist and that they contain only one of the [combination of fields](/api/guides/import-api/import-commands.md) that uniquely identify a resource. The identifiers of the resources used to identify another resource are also validated.

Note the following character limits for resource names:

| Resource type      | Number of characters |
| ------------------ | -------------------- |
| Asset              | 1 - 2 000            |
| Domain             | 1 - 255              |
| Community          | 1 - 255              |
| External system ID | 1 - 36               |
| External entity ID | 1 - 255              |