Historical clue formulations

• Nipple rings — 2024-02-04
• Colored rings — 2021-09-10
• Biological rings — 2019-05-03
• Colorful circles — 2019-03-21
• Anatomical rings — 2018-08-21
• Eye parts bordering on pupils — 2015-08-08
• Iris features — 2015-01-31
• Biological rings — 2006-08-13
• Anatomical interstices — 2003-10-11
• Anatomical rings — 2001-06-24
• Iris features — 2001-01-28
• Pupil surrounders — 1999-06-25
• Areas between the veins of a leaf — 1998-09-19
• Rings of color — 1995-05-19
• Rings of color — 1994-06-07