Character (of a navigation light)
Alternative term: Characteristic (of a navigation light)
The distinctive colour or periodic rhythm (or both) of a navigation light, enabling it to be identified.
Reference: C.I.E. (modified)
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