Transwiki:CAVOK claims the common meaning is "Clouds and Visibility O.K." and there is also "Clear and Visual Overcast". Dmcdevit·t 09:55, 19 April 2007 (UTC)
This is legit, but according to the following FAA link, the term is not used in the USA. 
Although not used in the U.S., the contraction "CAVOK" (ceiling and visibility OK) replaces visibility, weather, and sky condition if: ...
I'm sure it is pronounced 'cav-oh-kay', so would that make it an acronym rather than an initialism.--Dmol 16:30, 23 April 2007 (UTC)
Cleaned and struck. — Beobach972 18:16, 11 August 2007 (UTC)