Stable stem
A stem that will still make sense after a redesign. paywall_viewed survives a new layout; blue_sheet_opened does not.
A Listenerpacketgrid method
Event grammar
Before we draw a lattice we agree a language. Event Grammar is the public spine of every studio: how a tap becomes a sentence two platforms can share.
Sentences, not tags
An event is a verb with an object: article_completed, permission_prompted, transfer_succeeded. Adjectives belong in properties. Platform dialects (Android’s camelCase, an old iOS prefix) get translated in a dictionary, not in production. If two squads cannot read the name aloud and mean the same moment, the name is not ready.
We borrowed the tone from copy-editing, not from schema registries. The registry can wait. The sentence cannot.
The four marks
Visible version
When meaning changes, the name changes. Frozen stems stay in the dictionary with a date. See the journal note on unversioned names.
Kill-list
Every experimental event gets an owner and a review date. Orphans are retired in the open, not hoped away.
Human owner
A named person in the product org, not “growth.” Grammar without an owner becomes folklore by the next quarter.
How it shows up in the studios
Cohort Signal Lab assumes a grammar already exists; week one is an inventory against that grammar, not a blank page. Taxonomy Atelier is the slower course for teams still arguing about stems. Funnel Forensics uses the grammar to spot ghost steps — events that fire before the user could possibly have done the work.
The Listening Seat includes the worksheets. If you want them annotated against your stream, that is a Packet Studio or Fellowship conversation.