---
title: SKStoreProductParameterAdNetworkSourceIdentifier
framework: storekit
role: symbol
role_heading: Global Variable
path: storekit/skstoreproductparameteradnetworksourceidentifier
---

# SKStoreProductParameterAdNetworkSourceIdentifier

A four-digit integer that ad networks define to represent the ad campaign.

## Declaration

```swift
let SKStoreProductParameterAdNetworkSourceIdentifier: String
```

## Mentioned in

Generating the signature to validate StoreKit-rendered ads Identifying the parameters in install-validation postbacks SKAdNetwork 4 release notes

## Discussion

Discussion This key is available for ad impressions that use SKAdNetwork 4 and later. The SKStoreProductParameterAdNetworkSourceIdentifier, also known as the hierarchical source identifier, replaces and extends the campaign identifier value, SKStoreProductParameterAdNetworkCampaignIdentifier. Ad networks and developers define the meaning of the hierarchical source identifier. This string represents an integer of up to four digits. You can encode information about your advertisement in each set of digits; you may receive two, three, or all four digits of the sourceIdentifier in the first winning postback, depending on the ad impression’s postback data tier. For more information about the value you may get in the postback, see Receiving postbacks in multiple conversion windows.