Using CONVERT with COLLATE to strip accents from Unicode strings

Today Mladen Prajdic  posted a on Twitter a SQL statement that captured my attention: (http://twitter.com/MladenPrajdic/status/9878219727)

SELECT CONVERT(varchar(50), N’æøåáäĺćçčéđńőöřůýţžš’) COLLATE Cyrillic_General_CI_AI returns aoaaalcccednooruytzs

If you notice the conversion to Cyrillic_General_CI_AI collation his shows an interesting mechanism for code page translation that we could not explain:

Why does Cyrillic_General_CI_AI or   Greek_CI_AI collation successfully convert accents to their base ascii [...]