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# kCMTagValueKey

A constant for use as a key during tag creation from a dictionary, whose value is the tag’s contained value.

```
extern CFStringRef const kCMTagValueKey;
```

## Discussion

Values for this key are of the type held by the [`kCMTagDataTypeKey`](/documentation/CoreMedia/kCMTagDataTypeKey) key of the enclosing dictionary. Ensure that your value can be safely cast to the appropriate type.

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