Historical clue formulations

• *Reciprocal exchange — 2026-03-16
• Foreign exchange? — 2025-11-22
• One hand washing the other, so to speak — 2020-10-02
• Fair trade — 2006-03-11
• Compensation (+) — 2002-06-13
• Fair exchange — 2002-04-30
• Fair exchange — 1995-12-06