# UserIdentityTypeRegistry A registry for user identity types. Assignable documents and document elements store user identity data as `Data` objects. In order for that data to be deserialized, the type to deserialize it as needs to be known to [`UserIdentityTypeRegistry`](/documentation/Assignables/UserIdentityTypeRegistry). Without registration of the user identity, custom types won’t be deserializable. ``` class UserIdentityTypeRegistry ``` ## Topics ### Registering an identity [`static func registerUserIdentityType(typeID: String, type: UI.Type)`](/documentation/Assignables/UserIdentityTypeRegistry/registerUserIdentityType(typeID:type:)) Registers a user identity type for use when deserializing the user identity from `Data`. --- Copyright © 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)