Historical clue formulations

• Naval officer: Abbr. — 2020-08-02
• Spock's rank: Abbr. — 2016-12-11
• Spock, e.g.: Abbr. — 2016-03-05
• Mr. Spock's rank: Abbr. — 2013-06-04
• Naval officer: Abbr. — 2010-04-25
• U.S.N. position — 2007-08-31
• One reporting to a capt. — 2006-12-01
• U.S.N. rank — 2005-05-18
• Naval leader: Abbr. — 2004-03-08
• U.S.N. rank below Capt. — 2004-01-06
• Naval position: Abbr. — 2003-02-20
• U.S.N. rank — 1995-12-21