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# MTLStoreAction.unknown

The system selects a store action when it encodes the render pass.

```
case unknown
```

## Discussion

Only apply this action if you can’t determine the store action when you create the render pass descriptor. You need to specify a store action before you finish encoding commands into the render command encoder. Refer to the [`MTLRenderCommandEncoder`](/documentation/Metal/MTLRenderCommandEncoder) and [`MTLParallelRenderCommandEncoder`](/documentation/Metal/MTLParallelRenderCommandEncoder) protocol references for further information.

---

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