Second, I was basing my model on the Atom Entry Document in the Atom Syndication Format, referencing this as a Published Language[1]. Following that model, I interpreted the Person construct[2] as a Value Object. A Person “has one required element, name, and two optional elements: uri, email.” An Entity must have an identity. Without extending or modifying the model, which element would you pick as the identifier? URI or email seem to make sense, but those are optional fields. Identifiers can’t be optional. The name field is not an appropriate identifier as more than one Person can have the same name (and thus different URIs and emails). Since there is no appropriate identifier, that leaves us with treating a Person as a Value Object within the Atom Syndication Format domain.

[1]: Domain-Driven Design, Part IV. Strategic Design, Chapter 14. Maintaining Model Integrity, Published Language
[2]: http://www.atomenabled.org/developers/syndication/#person