Originally Posted by
aphoward13
R is the fare bucket for any upgrades you would get as a Gold member. PN is used for GS (and instant upgrades on Y/B fares, and M for 1K).
Clarification on the PN bucket for instant upgrades. PN is the upgrade bucket for instant upgrades for GS and 1k on Y, B, M. RN is used for instant upgrades for Plat and below on Y, B fares.