Historical clue formulations

• Call again — 2022-09-20
• Call back — 2022-05-18
• Phone button — 2015-10-16
• Modern phone feature — 2004-12-29
• Telephonic timesaver — 2004-09-04
• Phone feature — 2003-12-23
• Automatic phone feature — 2001-07-09
• Modern phone feature — 1997-12-17
• Phone feature — 1995-05-14
• Modern phone option — 1994-05-20