Historical clue formulations

• Surround — 2026-04-12
• Fence off — 2020-01-28
• Wall off — 2019-01-30
• Pen — 2016-06-30
• Corral — 2014-08-08
• Pen — 2010-06-27
• Hem in — 2008-04-23
• Wall in — 2007-08-09
• Pen — 2004-03-06
• Surround — 2003-09-17
• Ring — 2002-10-06
• Cocoon — 2001-11-17
• Pen — 1998-03-01
• Fence in — 1994-05-17