Originally Posted by
jackal
Correct.
Although I'm not sure if even a full Y ticket on DL confirms directly into F if no upgradeable space is available. I'm less familiar with DL than with UA, but on UA, even as a 1K, if you buy full Y, there must still be R space (upgradeable space and the equivalent of U on AS) for an upgrade to be confirmed. I assume it works similarly on DL.
The UA statement is incorrect. On United full Y fares purchased by a Premier 1K (or other Premier member) can be upgraded immediately to F, as long as F is available. To upgrade B fares (and M fares for 1K's) PN needs to be available. It varies, but PN availability is often one or two less than F availabiloiy. R is needed for upgrades done using miles, RPU's and GPU's. R varies greatly and could be zero even if no F seats are sold yet.