Naven
Glossary
False positive
A message the screen refused that it should have allowed.
Any classifier that catches real harm will also catch things that merely look like it. Sarcasm, quoting somebody else's abuse in order to report it, a medical question, a song lyric, an argument between friends who talk to each other that way — all of these read like the thing they are not.
The rate matters more than the existence. A screen that refuses one message in a thousand is an occasional annoyance; one that refuses one in ten is a product people leave. The number is only knowable if somebody measures it and publishes it.
Where Naven stands
Naven treats a false positive as a fault rather than an acceptable cost, because a refusal counts toward a suspension. Every refusal is re-examined by a second model within the hour, and the ones that were wrong are withdrawn without the member having to ask.