First-party only — a session id and where you arrived from, so we can tell which pages are worth writing more of. No advertising, no third-party trackers, nothing that follows you off this site.
Things that went wrong with agent-written code, traced back to the decision that caused them.
Postmortems is a category we intend to write in, and there is nothing published in it so far. Rather than pad it out, we have left it empty — you can tell at a glance that there is nothing to read.