Historical clue formulations

• Swear — 2026-05-03
• Certify — 2024-10-09
• Vouch for, with "to" — 2022-07-31
• Validate, with "to" — 2021-08-26
• Swear (to) — 2021-03-08
• Certify formally, with "to" — 2020-07-12
• Swear — 2020-04-25
• Swear (to) — 2017-06-26
• Bear witness (to) — 2016-12-26
• Bear witness — 2016-07-10
• Swear — 2016-05-13
• Swear — 2015-11-13
• Certify — 2014-01-19
• Bear witness (to) — 2013-11-06
• Certify (to) — 2013-08-11
• Swear — 2012-05-23
• Bear witness — 2011-03-20
• Warrant, with "to" — 2011-03-03
• Certify (to) — 2010-04-19
• Bear witness — 2009-12-13
• Affirm, with "to" — 2009-09-13
• Swear (to) — 2009-08-26
• Swear to — 2008-10-28
• Swear — 2008-03-29
• Bear witness — 2008-01-14
• Bear witness — 2007-01-14
• Swear (to) — 2005-11-16
• Swear — 2005-04-01
• Swear (to) — 2004-12-27
• Swear — 2004-08-06
• Swear — 2004-06-03
• Swear (to) — 2004-05-03
• Validate — 2004-04-03
• Swear — 2003-09-18
• Certify, with "to" — 2001-10-20
• Swear (to) — 2001-10-14
• Certify — 1999-08-08
• Bear witness — 1998-04-29
• Bear witness — 1997-01-15
• Certify — 1996-12-22
• Swear (to) — 1996-05-29
• Give one's word — 1995-12-23
• Swear — 1995-07-01
• Bear witness — 1995-06-28
• Say under oath, with "to" — 1995-05-08
• Corroborate — 1994-08-21
• Swear (to) — 1994-06-06