12 August 2026
Event naming that survives a second product line
The first product line usually names events after screens. `home_tapped`, `paywall_seen`, `settings_opened`. It feels local and kind. Then a wearable arrives, or a tablet mode, or a white-label cousin, and every name is a room in a house that no longer exists.
In Cohort Telemetry Studio we ask people to rename ten live events before we look at a single chart. The rule is small: object, action, context. `playlist.saved` with a property for surface. `checkout.started` with a property for entry. The object should still make sense if the screen is redesigned by a contractor who has never met you.
`click` is banned, not because clicks are unreal, but because they describe a finger instead of a decision. A decision can be implemented on voice, on a complication, on a car screen. A click cannot without becoming a metaphor you will argue about later.
Identity is the other inheritance problem. If `user_id` means “account” on mobile and “device” on the wearable, your second product line will look more successful than it is. Write the join down. Put it in the tracking plan in a paragraph a new hire can read on a Monday. If the paragraph needs a diagram, the join is not ready.
People worry that grammar is bureaucracy. It is the opposite. Bureaucracy is a Slack thread from 2023 explaining why `cta_3` still fires. Grammar is a list short enough to print. When the wearable team asks whether they need a new dialect, the answer should be a property, not a committee.
If you want a supervised rewrite, the Event Taxonomy Residency exists for that week of discomfort. If you only want the rule: name the thing the business will still sell in three years, then the action a person took, then the context that will change. Screens are context. They are not objects.