Starting with #Fedify v1.0.0, the term handle throughout Fedify will only be used to refer to a fediverse handle (e.g., @hongminhee@fosstodon.org). An actor's internal unique ID (e.g., b379dbdc-3b4f-4ef4-88c2-fc25632d1c22) will be referred to as identifier and a WebFinger name (e.g., hongminhee) will be referred to as username. The term handle in the API will be retained for the time being for backwards compatibility, but a deprecation warning will be logged and will be deprecated in the future.