Reciprocal of the period.
Symbol f, ?
Note: 1 When the independent variable is time, the unit of frequency is the hertz.
Unit hertz (Hz) lHz = l/s
Note: 2 In Britain, France and U.S.A. cycles per second (cps or c/s) have been used for "hertz".
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM