http://www.summitpost.org/fact-sheet/17 ... facts.html
The F, D, AD, etc. used by UIAA are the same "overall" rating for climbs as are NCCS Grades in the USA.
UIAA "Grades" of I, II, III, etc. are individual pitch ratings as are Class 4, 5.2, 5.7, etc. in the YDS system.