---
title: "proprietaryData(for:)"
framework: CarKey
role: symbol
role_heading: Instance Method
platforms: [iOS 16.0+, iPadOS 16.0+, Mac Catalyst 16.0+, macOS 13.3+, watchOS 9.0+]
path: "carkey/vehiclereport/proprietarydata(for:)"
---

# proprietaryData(for:)

Retrieves the proprietary data associated with one of the vehicle’s functions.

## Declaration

```swift
func proprietaryData(for function: FunctionIdentifier) throws -> Data?
```

## Parameters

- `function`: The function identifier for the given vehicle feature. If you specify an unknown feature, this method throws an error. For a list of the vehicle’s supported features, see the doc://com.apple.CarKey/documentation/CarKey/VehicleReport/supportedFunctions property.

## Return Value

Return Value A data object, or nil if no data was present for the specified feature.

## Discussion

Discussion When it receives new data from a vehicle, the system updates the vehicle report and notifies the session delegate. Call this method to retrieve any data associated with a particular feature of your vehicle.