---
title: NSMigrationEntityPolicyKey
framework: coredata
role: symbol
role_heading: Global Variable
path: coredata/nsmigrationentitypolicykey
---

# NSMigrationEntityPolicyKey

Key for the entity migration policy object.

## Declaration

```swift
let NSMigrationEntityPolicyKey: String
```

## Discussion

Discussion To access this key in a custom value expression string in the Xcode mapping model editor use $entityPolicy.

## See Also

### Constants

- [NSMigrationManagerKey](coredata/nsmigrationmanagerkey.md)
- [NSMigrationSourceObjectKey](coredata/nsmigrationsourceobjectkey.md)
- [NSMigrationDestinationObjectKey](coredata/nsmigrationdestinationobjectkey.md)
- [NSMigrationEntityMappingKey](coredata/nsmigrationentitymappingkey.md)
- [NSMigrationPropertyMappingKey](coredata/nsmigrationpropertymappingkey.md)