Anthropic injects text into the conversation triggered by certain conversation topics. This happened to me in relation to some red-teaming related discussion that was adjacent to something “sensitive”, I think sex, and Claude got confused about why I had said some kind of warning and mentioned it it’s response. After a back and forth it was clear that some extra warning to answer but avoid anything inappropriate had been inserted into the conversation.

Claude also sometimes mentions getting messages from classifiers, probably related to auto mode. Amusingly enough, when this happens to a subagent/fork, the orchestrator will call these " hallucinations by the subagent"