Originally Posted by
sfo3388
Please check the most recent update on United.com:
Star Alliance Upgrade Award | United Airlines
For EVA, only K class (the most expensive premium economy class) is eligible for Star Alliance Upgrade using United miles. Y and B are not eligible anymore.
If you click the link for "See which
class of service is associated with each fare class listed." and then under "Star Alliance partner airlines", you will see that it says:
Business class C and D fares and Economy class Y and B can be upgraded, and other fare types may also be eligible depending on the airline.
So the list just means that for EVA, K class can be upgraded
in addition to the usual Y and B class.
Otherwise Air Canada also only has one fare class listed (O), which wouldn't make much sense either.