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# HMCharacteristicTypeIdentifier

The identifier for an accessory.

```
let HMCharacteristicTypeIdentifier: String
```

## Overview

In the Input Source Ordering Profile, `HMCharacteristicTypeIdentifier` identifies an instance of the Input Source service. The value for each instance of this service must be unique within the list of input source services linked to a television service. A value of `0` isn’t valid for the instance of this characteristic included in the Input Source service.

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