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# sourceIdentifier

A number that identifies the source of the attribution.

```
var sourceIdentifier: UInt8 { get }
```

## Discussion

This property contains an integer, between 0 and 255, that identifies the source of the attribution. For example, for an ad, `sourceIdentifier` might contain a campaign identifier so the advertiser can measure the effectiveness of different advertising campaigns.

This field corresponds to the `source_id` field of a web attribution.

---

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