Historical clue formulations

• Acknowledge — 2026-08-16
• Acknowledge silently — 2025-07-13
• Silently acknowledge — 2024-01-17
• Say yes to without saying "yes" — 2020-04-17
• Signal silently — 2018-04-28
• Greet silently — 2013-05-26
• Silently greet — 2012-09-09
• Tacitly agree with — 2011-05-01
• Tacitly acknowledge — 2011-01-18
• Acknowledge tacitly — 2008-03-30
• Tacitly acknowledge — 2008-03-22
• Show agreement with — 2006-04-23