Historical clue formulations

• Signal as a conductor might — 2021-02-03
• Signal when to begin — 2019-08-15
• Bring up to date, say — 2019-04-28
• Keep informed — 2016-05-28
• Bring up to speed — 2015-05-28
• Bring up to speed — 2014-08-31
• Bring up to speed — 2014-07-25
• Make aware — 2008-12-10
• Give a hint — 2008-12-07
• Make aware — 2008-08-11
• Give hints to — 2007-06-11
• Give a signal to — 2007-01-18