Originally Posted by
cmd320
As GlobalMatt notes, EF is ExpertFlyer.
J5 would mean a total of five seats in business class for sale (the premium cabin on two class domestic flights is considered 'business' class despite being marketed as 'first'). W is premium economy, though when flown on domestic segments, it's offered as Main Cabin Extra.
Keep in mind, OP is trying to maximize upgrade chances, so I don't think trying to do LAX-JFK-CLT is going to really help that despite there still being a couple seats available. As a GLD, LAX-JFK is very unlikely to clear.
Very good point here and thank you for pointing this out. I did PM the OP and let them know they'd be better off calling AA and asking for either a cash upgrade or a points upgrade. My apologies for not specifying this in the thread!