Three system prompts reportedly cut Claude's hallucinations "dramatically," and they're sitting in plain sight

A Reddit user discovered three system prompts from Anthropic's official documentation that reportedly reduce Claude's hallucinations dramatically: allowing Claude to say 'I don't know', requiring citations, and using direct quotes for factual grounding. While effective for research tasks, these prompts reduce creative output, so the user recommends building a toggle to switch between a strict research mode and a default free-thinking mode.