Historical clue formulations

• ... "got" or "tell"? — 2016-06-05
• "Let this be our little secret" ... with a hint to 18-, 23-, 50- or 54-Across — 2013-11-06
• "Let this be our little secret" — 2000-10-02
• "Shhh..." — 2000-01-03
• UXS — 1997-09-28