<!--
{
  "availability" : [
    "iOS: 13.0.0 -",
    "iPadOS: 13.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "ARKit",
  "identifier" : "/documentation/ARKit/ARSession/CollaborationData/Priority-swift.enum/optional",
  "metadataVersion" : "0.1.0",
  "role" : "Case",
  "symbol" : {
    "kind" : "Case",
    "modules" : [
      "ARKit"
    ],
    "preciseIdentifier" : "c:@E@ARCollaborationDataPriority@ARCollaborationDataPriorityOptional"
  },
  "title" : "ARSession.CollaborationData.Priority.optional"
}
-->

# ARSession.CollaborationData.Priority.optional

A priority that indicates that collaboration can continue without this data.

```
case optional
```

## Discussion

ARKit sets the data [`priority`](/documentation/ARKit/ARSession/CollaborationData/priority-swift.property) to [`ARSession.CollaborationData.Priority.optional`](/documentation/ARKit/ARSession/CollaborationData/Priority-swift.enum/optional) when the data is important and time-sensitive but the session can continue if it’s not received.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)