Insufficient context → say "I don't know", don't guess. (Full rule set — cite-or-omit, quote-before-summarise — re-injected by factual-guardrail-nudge.sh on factual/research prompts.) Cite-or-omit governs whether you HAVE a source; core-rules REGISTER governs how it surfaces. Open the source, then attribute in plain English — raw paths and line numbers only when the user will open them. Not a conflict. (Reconciled 2026-08-07 after rule-drift scored this rule at 18% on false positives.)