# identifier

The identifier property represents any kind of identifier for any kind of [Thing](https://schema.org.ai/Thing), such as ISBNs, GTIN codes, UUIDs etc. Schema.org provides dedicated properties for representing many of these, either as textual strings or as URL (URI) links. See [background notes](https://schema.org/docs/datamodel.html#identifierBg) for more details.

## Expected Types

| Type | Description |
|------|-------------|
| [PropertyValue](https://schema.org.ai/PropertyValue) | A property-value pair, e.g. representing a feature of a product or place. Use the 'name' property for the name of the property. If there is an additional human-readable version of the value, put that into the 'description' property. Always use specific schema.org properties when a) they exist and b) you can populate them. Using PropertyValue as a substitute will typically not trigger the same effect as using the original, specific property. |
| [Text](https://schema.org.ai/Text) | Data type: Text. |
| [URL](https://schema.org.ai/URL) | Data type: URL. |

## Used on Types

| Type | Description |
|------|-------------|
| [Thing](https://schema.org.ai/Thing) | The most generic type of item. |

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Quoted from Schema.org 30.1, https://schema.org/identifier, under CC BY-SA 3.0. Served by the Org.AI Foundation at https://schema.org.ai/identifier.