Historical clue formulations

• Prefix meaning "egg" — 2026-03-16
• Egg: Prefix — 2023-09-24
• Egg: Prefix — 2022-04-14
• Egg: Prefix — 2020-09-02
• Egg: Prefix — 2019-10-15
• Egg head? — 2019-06-30
• Lead-in to duct — 2017-07-28
• Egg: Prefix — 2017-02-10
• Egg: Prefix — 2015-09-16
• Egg: Prefix — 2014-09-28
• Egg: Prefix — 2013-11-27
• Egg: Prefix — 2013-10-29
• Prefix with duct — 2013-04-29
• Duct lead-in — 2012-04-21
• Prefix with posit — 2012-04-05
• Egg: Prefix — 2012-02-29
• Egg: Prefix — 2011-10-30
• Egg: Prefix — 2011-08-31
• Prefix with duct — 2010-04-27
• Duct opening? — 2009-02-20
• Egg: Prefix — 2009-02-15
• Egg head? — 2008-09-06
• Egg: Prefix — 2007-10-02
• Duct opening — 2007-07-07
• Duct opening? — 2006-10-06
• Prefix with duct — 2005-08-23
• Prefix with sac or duct — 2005-06-14
• Prefix with posit — 2005-03-12
• Egg: Prefix — 2005-02-24
• Prefix with duct — 2004-02-08
• Prefix with posit — 2003-09-27
• Egg: Prefix — 2003-08-20
• Prefix with sac — 2002-11-30
• Prefix with duct — 2001-12-09
• Prefix with posit — 2001-09-15
• Prefix with duct — 2001-05-13
• Egg head? — 2000-09-30
• Duct opening? — 1999-11-17
• Egg: Prefix — 1999-05-18
• Prefix with sac — 1999-02-27
• Prefix with duct — 1998-07-19
• Prefix with duct or form — 1997-05-11
• Egg: Prefix — 1996-12-25