A History of Short Words

From the New York Times Crossword Puzzle

KPH

Fri, 19 May '23
Autobahn abbr.
Mon, 21 Mar '22
Speed measure on European hwys.
Sat, 20 Nov '21
Metric speed meas.
Sat, 30 Oct '21
Overseas rate: Abbr.
Sun, 19 Sep '21
Overseas speed meas.