Other European Frequent Flyer Programs - CSA eligible classes for Upgrade

Can anyone advise me which travel classes on CSA are eligible for upgrade. There was a webpage at one point with the classes on it but I can't seem to find it and CSA change them so frequently, I've lost track

thanks

Can anyone advise me which travel classes on CSA are eligible for upgrade. There was a webpage at one point with the classes on it but I can't seem to find it and CSA change them so frequently, I've lost track

thanks

I found the page, sorry.

https://secure.csa.cz/en/ok_plus/okp_earn_miles/okp_czech_airlines.htm