Writing order and customer notes. This is not the same as the timeline comments. We mention it here because this frequently makes for an acceptable fallback approach.
Using a timeline event as a Mechanic event. This means that Mechanic tasks can't run in direct response to a new comment (or other timeline event).
Reading the name of the staff person who left a comment, or the name of the app responsible for another event.
Creating, updating, prefilling, or deleting timeline comments.