Super Property Registration

Super property registration means registering a property once so it automatically attaches to every subsequent event, without repeating it by hand in each call.

Super property registration is a way to hold a stable context across all of a session's or user's events; app version, experiment group, or subscription type are things needed on nearly every event, and repeating them in each call is both tedious and error-prone. Its key difference from a user property is that a super property attaches to events, not the profile, and has no effect on past events; it works from the moment of registration onward. It carries two cautions: because it attaches to every event, registering a sensitive or high-cardinality value can pollute all the data; and because it lives in device memory, it must be cleared on logout or it leaks to the next user. Super property registration should be used with discipline, only for context that truly matters on every event.