# enum DeliveryForecastSource (v202508)

**Service** [ForecastService](https://developers.google.com/ad-manager/api/reference/v202508/ForecastService.DeliveryForecastSource) **LineItemService** **Dependencies** [LineItemSummary](https://developers.google.com/ad-manager/api/reference/v202508/LineItemService.LineItemSummary) ▼ **DeliveryForecastSource**

Strategies for choosing forecasted traffic shapes to pace line items.

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Namespace
:
    `https://www.google.com/apis/ads/publisher/v202508`

| Enumeration | Description |
|---|---|
| `HISTORICAL` | The line item's historical traffic shape will be used to pace line item delivery. |
| `FORECASTING` | The line item's projected future traffic will be used to pace line item delivery. |
| `CUSTOM_PACING_CURVE` | A user specified custom pacing curve will be used to pace line item delivery. |
| `UNKNOWN` | The value returned if the actual value is not exposed by the requested API version. |