Historical clue formulations

• Essences — 2025-01-04
• Kernels — 2024-07-13
• Cruxes — 2022-05-06
• Hearts — 2018-08-11
• Piths — 2017-12-29
• Essences — 2017-11-09
• Main points — 2017-08-15
• Main points — 2016-12-11
• Hearts — 2005-08-13
• Cores — 2000-09-04
• Nubs — 1999-07-11
• Basic ideas — 1998-11-22
• Essences — 1998-10-26
• Central points — 1998-03-31