Historical clue formulations

• Acknowledges, in a way — 2026-05-30
• Discreetly acknowledges — 2025-04-13
• Acknowledges tacitly — 2024-10-04
• Acknowledges without a sound — 2014-11-21
• Gives a passing acknowledgment — 2011-09-02
• Signals, as to an auctioneer — 2008-12-24
• Acknowledges nonverbally — 2007-10-23
• Acknowledges in passing — 2006-12-12
• Signals — 2006-09-17
• Signals — 2005-08-05
• Greets nonverbally — 2005-01-09
• Acknowledges in passing — 2003-12-28
• Signals, as to an auctioneer — 2002-02-25